- “It's your power, isn't it!?”
- — Midoriya to Todoroki in the Sports Festival Arc
Izuku was the breaking point that he helped Shoto embrace himself, not by making him give into his father's will, but by making him realize that the connection between the quirks of a person and their parents are not what matters most, but being able to recognize it as the quirk that they as a person have. Midoriya even being super shy faced Hero Number 2 (father of Shoto) to defend the Todoroki. One of the most iconic lines in the show stems from this scene, "It's your power, isn't it?!". Izuku helping him during the fight, even knowing that Shoto was only using half his power and would most likely beat him when accepting his fiery side, was a sign that Izuku cared much more about helping Todoroki than winning.
After the fight, the two became closer, creating a strong bond of friendship. Then Shoto started to show less difficulty in approaching people and demonstrating how he feels. Izuku began to strive even more to improve his individuality as he becomes more confident.
During Todoroki's fight against Bakugou, seeing that Todoroki due to the emotional state could not use his full power, Midoriya shouts in the middle of the audience "Don't lose! Do your best!" Todoroki listens and feels something that activates his firepower, but in the end, Todoroki cannot maintain the fire and because of the defeat, Bakugou does not accept the victory.
After the cavalry battle, Shoto told Midoriya everything he thought, both his past and his suspicions, and after all, both accepted their rivalry, with Bakugou listening between the two.
In the Vs. Hero Killer arc, Izuku was stuck in a bind while attempting to save Tenya Iida from "Hero Killer" Stain. This caused him to secretly send out a signal to his location on his phone, which Shoto-- although hesitantly, questioning whether he would really be in trouble- was the first and only one to comply and come to his area. Showing that despite not knowing each other for long, they have a deep understanding of each other, along with the fact that despite the Hero Killer not being an immediate threat to Midoriya's life instead being Tenya Iida the one in danger of dying, Todoroki still knew something was wrong and left his father and everything behind with the initial belief that Midoriya was in danger/something was wrong.
Later on during the aftermath of the fight, Shoto became angry on behalf of him and his friend Iida for having trouble against the law despite the fact they stopped a serial killer-- showing both his moral strength and how important Midoriya is to him along with Iida.
During the Forest Training Camp arc, Midoriya is shown to be in a bind concerning what to do with Kota Izumi, given how the child seems to hate heroes and Midoriya always wanting to help didn't know how to handle the situation that wasn't in an intrusive way to the child. So, later on Todoroki notices Midoriya's concern and Midoriya asks for his advice, showing how much he trusts and respects Todoroki's words. Todoroki because of this reminiscences of how Midoriya saved him by getting involved with his problems when he didn't ask for it, and tells Midoriya that words should always be accompanied with actions with the quote: "Even he's told all the right things, if you don't know his background then you'll only succeed in annoying him" along with "The important thing is, what the person who's saying it has done...and what they're doing now. I think that words are always accompanied with deeds.", In which Midoriya smiles and agrees with Todoroki.
Then, later on during the Muscular vs. Midoriya fight to save Kota, he remembers and uses the words of advice Todoroki told him and tells Muscular "A hero's job is to save people's lives. Turning words into actions!" as he goes One-For-All 100% Percent.
Additionally, in season 3, when Midoriya is in the hospital, Todoroki appears alone to visit Midoriya in the hospital. Showing how much Todoroki cares for Midoriya in such a short time knowing each other, given how rough their relationship started.
They both have things in common-- such as their admiration for All Might and the desire to become great heroes-- accompanied by their differences, which might be the reason their dynamic is very appealing to the fans. They also both have great respect and admiration for each other, both showing support and amazement when either of them have showed improvement with their quirks or have done something admirable personality-wise.
Manga scene developed in the dining room. Izuku is saddened by the events that have happened with Eri and the fact that all the pressure from the mission falls on some of his colleagues and himself. He cannot talk to his best friends, and says "Heroes can't cry." Todoroki gives him a serious considerate look and says "Even heroes cry sometimes." In an attempt to comfort him, he and Iida offer a portion of their food (Todoroki's being soba noodles).
In the Endeavor vs. High End Nomu Battle Todoroki watches as his father is in a gruesome battle with the High End Nomu, Todoroki's shown to worry for his father despite their history, Midoriya is one of the first ones to notice his presence and worry for Todoroki's feelings as well. When the battle is over, Endeavor coming out victorious, Todoroki collapses in relief and Midoriya is one of the people who come to comfort him as well.
After the battle, Todoroki is given permission to go home and check on his father, Endeavor arrives and remembers how during his battle he remembered all the past mistakes he's done to his family and decided to atone for his actions, Natsuo Todoroki, Endeavor's third born child gets angry at him. However, Shouto is shown to be somewhat more accepting of Endeavor trying to atone and change as he remembers how Midoriya changed him with those simple words during the Sports Festival, Todoroki remarks this by saying: "One small inspiration can completely change a person. I know that better than anyone."
During the Joint Training Arc, Todoroki is paired in a battle with Tetsutesu Tetsutetsu, however Tetsutetsu's quirk shows to be complicated for Shouto's quirk as both his ice and fire don't seem to back him down, Todoroki then resorts to using one of his father's special moves and remembers Midoriya's "Its your quirk not his!/It's your power isn't it?!" and this fuels his fire to go to their most powerful state yet.
Midoriya's was the first appearance of one of the many quirks he will receive from within One for All, Black Whip. The battles are shown on a screen for both of the classes to observe, resulting in everyone seeing this new power. When questioned about it in front of the class, Midoriya brushes it off as a new manifestation of his quirk. After the training, Todoroki sets out to look for Midoriya, after he finds him, he is shown to be disappointed that Midoriya didn't trust him enough to tell him about this quirk, and is also remarks how disappointing it is for him after Midoriya went all out to make Todoroki use his full potential when Midoriya, in Todoroki's eyes, wasn't using his power to his full potential either. Midoriya is shown to worry and quickly reassures him that Blackwhip is just an extension of his original quirk and that it is a recent development as well. Todoroki who is very trusting of Midoriya believes him and compliments Midoriya for be his development for his quirk is amazing, Midoriya also compliments Todoroki for his fire reaching incredible levels as well, Todoroki takes this aside saying that he still has a lot to learn.
Mt. Lady & Student Interviews: Mt. Lady is invited to U.A. to perform an interview practice with the class. Todoroki is one of the first ones to go, showing off his own quirk super moves and how he handles interviews, Mt. Lady making various comments regarding his looks and Todoroki being adorably oblivious to this, in the audience Midoriya is shown smiling proudly and remembering Todoroki's words of improving his quirk. After all the turns, its finally Midoriya's turn and he is comically shown to be nervous and going stiff in his anxiousness. At the end of the chapter we see Midoriya going to Todoroki and saying "You don't get nervous, do you?"
At the Christmas Party, it is discussed were Midoriya will go for his internship, as Nighteye is now unable to run it and the agency is too busy to take a new intern. Bakugo also will not return to his previous internship. After the party, Todoroki invites both of them to his dad, Endeavor's agency.
At the end of the week in Endeavor's agency the interns, Todoroki, Bakugo, and Midoriya are invited to dinner at the Todoroki household by Fuyumi, Todoroki's sister. Here Shoto Todoroki acknowledges that he considers Midoriya and Katsuki to be his friends. After the meal Midoriya, Shoto, and Bakugo help clean up an Fuyumi apologizes to her brother for 'making them all help out' He tells her that its fine and that 'Midoriya would feel even worse if they didn't let him help out', proving that he has observed the type of person Midoriya is. Some family issues popped up during the dinner and this resulted in Natsu Todoroki expressing anger at what Endeavor had done and leaving the room. As Shoto's friends come back from putting dishes away they overhear Fuyumi and Shoto having a conversation about their father. Bakugo makes his and his childhood friend's presence known. Midoriya tells Shoto that he looks like he was preparing himself to forgive his father, and adds that if he really hated him, it was fine if he never forgive him. But you're not like that. You're a kind person. That's why it looks like... you're waiting showing that once again Midoriya might know more about Shoto than he knows about himself.
As the guests are getting into the car to leave Fuyumi pulls Midoriya aside to thank him for being Shoto's friend, to which Midoriya responds with 'Oh that's- the pleasure is all mine!'. She does not do the same with Bakugo, but that might be because Bakugo is scary. We can also see that when Endeavor drive the guys back, Midoriya it's sitting between both boys (with Todoroki at left and Bakugo at right), also Todoroki asked Midoriya that if Uraraka and Kirishima had something similar too, which Midoriya asks in answer that they still had to study for the finals too, and Midoriya asks Todoroki if he could help him with his English later. After dinner as the interns and Endeavor are heading to UA, they are attacked by a villain who has Shoto's remaining brother, Natsu as a hostage. Using what they have learned in their week at the agency the three take action to stop the villain and rescue the elder Todoroki brother. The UA students worked together well, showing the bond of teammates and the complicated friendship that formed between them.
Make it! Do-or-Die Survival Training
The both guys didn't interact in the first part of the OVA, but it's clear that both appeared together. In the second part of the OVA, it's seen Midoriya, Todoroki and Bakugo working together for getting out of the place from where it was flooding. Midoriya had set a quick plan before that; Todoroki had to use his ice to impulse the 3 guys to the top of the building to get out of there while Bakugo exploded the roofs that were in their way for making it out. When the plan started, something went wrong when Midoriya kicked the first roof; a rock knocked his front which made him almost fall, but Todoroki was quick enough for grabbing his hand for preventing him to fall, while screaming in horror his name. It's seen in a scene later that after Todoroki caught Midoriya, he leaned Midoriya in his arms, since Izuku was injured about the rock that hit his front. and couldn't move for a second. After falling several floors, everything was safe, but Todoroki noticed Midoriya in the ground. Then quickly Shoto runs to him and calls for his name while Midoriya was unconscious. Luckily, seconds after, Midoriya woke up and saw a worried Todoroki in front of him, Shouto after seeing Izuku awake, he says that he's glad that Midoriya wasn't injured at all while giving him a small smile, which Midoriya thanks Todoroki saying that it was thanks to him and Bakugo that they could prevent the flooding.
My Hero Academia: School Briefs
During the Parents Day Event, the student's family members are recruited for a rescue mission for the students. Midoriya originally has a plan however this backfires at first, and the class goes completely havoc as everybody has no idea on how to save the family members, Midoriya seeing his plan backfire and the class going into chaos gets discouraged, Todoroki noticing his feelings reassures Midoriya saying "They all know we're in a tight spot. Our only chance of a sneak attack is from you" which Midoriya questions "You think?" And Todoroki responds,"You're good at that. Smashing the unsmashable and all that." Izuku, moved by Todoroki's faith in him, almost cries but holds back his tears as they have parents to save.
In another scene, Todoroki visits his mother and they have a brief conversation about Izuku. During this, he bashfully states that "He's something special.", to which his mother smiles softly and gets teary eyed, replying, "It seems like you've made quite a friend."
In the My Hero Academia: School Briefs Vol. 2 , the students are on their way to a school trip, during the bus trip Aoyama is shown to get motion-sickness and Todoroki being his partner in the seats gives up his seat to make Aoyama lay down. Todoroki instead opens up one of the aisle seats to sit down however this are shown to be small and uncomfortable, Midoriya feels bad about Todoroki having to give up his seat, then tells Todoroki that they can switch up seats, however Todoroki declines and sits down, making comments on how the seat is too small but it's fine, Midoriya can't take it and keeps insisting to switch up seats, commenting on how it's better as he is smaller than Todoroki so it won't be as comfortable, much to Todoroki's amusement, but he reassures him that he's fine.
As the school bus trip goes on the students chose to play games, Midoriya being the All Might fanboy is makes a game of Hero Trivia. He asks a rather complicated question regarding All Might and an old TV show where All Might saves a puppy, Midoriya asks what is the puppy's name. While everyone else pokes fun at him, ignores him, or comments on how they should play a more fun game, Midoriya gets embarrassed, however Todoroki is the only one to take his question into consideration and says softly, "Is it Pochi?" To which Midoriya, excited that someone actually played along, replies "So close! Ponta, actually!"
In the My Hero Academia: School Briefs Vol.5, it's seen that Todoroki headed to Midoriya's room to give him a mechanical pencil that Midoriya left in his room while both were studying English in Todoroki's room. Izuku thanks Shouto for bringing it back to him, then Todoroki peeks Izuku's room and says that it's full of All Might, which makes Midoriya scratch his head a bit in embarrassment. Todoroki then adds that he wanna try to put a figurine on his room too and then Midoriya's eyes glittered to him and then explains to Todoroki all the collection of All Might that he had on his room, and he even showed, and wanted to give Shouto one of his rarest All Mights without any hesitation, Shoto was shocked about that, but before he could say anything, Midoriya interrupts him by saying that he has already 2 of them, so there was no problem on giving Todoroki one. By this action, Todoroki declines the offer saying that he might accidentally drop and break it. Izuku says that it's all right, but in a disappointed tone, Todoroki noticed this and then for cheering him up, he asked if he ever want to see it, he can come by again to his room, which made Midoriya gave him a bright smile while agreeing with that offer, which made Shoto's face soften by this.
Behind The Scenes
- Interviewer – “What moment do you think it was that you got to “really act as Todoroki” for the first time?”
- Yuki Kaji (Shouto) – “Todoroki is a person who is still in the midst of changing, and to be honest I still feel some frustration sometimes, but it was definitely during his one-on-one tournament battle fight with Midoriya. The resolve and words that Midoriya expressed…… all of that seems to have pulled out Todoroki’s true self. I see it as maybe Todoroki’s “visible emotions” were his fire power. I think Todoroki had frozen his own heart, and Midoriya lit a fire in it for him.”
- — “A Fire Lit in a Frozen Heart”
- Yamashita Daiki (Midoriya) – ““Todoroki-kun wasn’t looking at anyone in the class. He made eye contact with them, but there was a coldness there that made you realize he wasn’t really seeing them. He was so focused on his anger towards his father Endeavor, so stubborn and proud, but now he really looks at everyone naturally. I’m happy to see Todoroki-kun genuinely talking with everyone now-- I think he probably spoke up because after having been through so many things together, he was able to notice the subtle differences in Deku.””
- Yuki Kaji – “(nodding) “I think Midoriya is probably the first friend Todoroki has ever made. There’s a lot about Todoroki’s life before entering U.A. High School that still hasn’t been revealed, but I think before entering U.A. he wasn’t thinking ‘I don’t need friends’, I think he had just never even realized the importance of having friends or relationships with people like that. I think his abilities and life experiences lead him to grow up faster than other kids, and maybe it looked like he was okay but… there were still some things he needed to work on. Midoriya created the opportunity for him to learn those important human things while he’s still at school-- And now it feels like he says ‘Midoriya’ every chance he gets (lol).””
- Yamashita Daiki (Midoriya) – ““I think they’re really good friends! And I think that ever since Todoroki-kun, Iida-kun, and Deku survived that life or death encounter (The Hero Killer Stain Arc in Season Two), there’s an unspoken understanding between them.””
- — The Two of Them Have an Unspoken Understanding 
- During the Todoroki vs. Sero fight, Midoriya sensed the feelings of Shoto's sadness, feeling a strong sense of wanting to help him and save him from his tragedy and his past.
- All Might comment on "Izuku preferred the possible defeat of himself than to see [Shoto] suffer".
- During the awards ceremony of the Sports Festival Todoroki tells All Might "Now I know why you're so interested in him"
- Todoroki's first word for season three was "Midoriya".
- In the My Hero Academia U.A. Survival Camp Seiyuu Event. During one of the Drama Skits, Midoriya, Bakugou, and Todoroki end up getting crushed under falling debris from a shopping mall building, Deku is the one that gets hurt.
- In chapter 245 of the manga, Midoriya calls Todoroki by his name; "Shoto". He likely meant his hero name.
- During the MHA Season 4 DVD Bonus Light Novel Excerpt, it's mentioned Midoriya helping Todoroki making an All Might's origami, since Todoroki wanted one for a letter that he was doing for his mother.
- In the School Briefs vol.5, it's mentioned that Todoroki had chosen katsudon (Midoriya's favorite food) instead of soba because they ran out of it while he was with his mom.
- In the 5th season's opening, both are seen chatting together.
- In My Hero Academia episode 90 — Shoto talked about how he knows that “something small can change a person” just like how Midoriya’s words at the Sport’s Festival changed him.
- Fuyumi – “Sorry for making you all help out”
- Todoroki – “Midoriya would feel even worse if we didn't let him help”
- — Fuyumi and Todoroki chat after dinner in chapter 244.
- Midoriya – “Todoroki-kun. You're preparing yourself for forgiving [Enji], aren't you?”
- Todoroki – “Eh?”
- Midoriya – “If you really hated him, i think it's fine if you never forgave him. But you're not like that. You're a kind person. That's why it looks like... you're waiting. But it's just not the right time yet...”
- — Midoriya's feelings towards Todoroki's relationship with Endeavor in chapter 244.
- Dabi – “Don't you know it's rude to meddle in other families' affairs!”
- Midoriya – “I'm meddling! Because Todoroki-kun is a precious friend!!”
- — Chapter 293
- Todoroki – “Midoriya?! MIDORIYA?! ANSWER ME PLEASE!”
- Midoriya – “I'm...okay...”
- Todoroki – “Here, lean on my shoulder so I can hoist you up! Bakugou help me pick him up!”
- Midoriya – “Its okay Todoroki-kun. I can...get up on my own...”
- — Survival Camp Seiyuu Event
The initials "Todo" and "Deku" were popularized by western fandom, while in Japan this ship is better known as TodoIzu. This is one of the most known and fan-supported due to the friendly and noble behavior they both forged in the anime/manga. TodoDeku is the most popular ship in Western fandom, and the second most popular in Eastern fandom. It is the most popular ship for Todoroki in both fandoms. Many who support TodoDeku do not like the ship BakuDeku, and typically support KiriBaku along with shipping TodoDeku.
A fan theory says that both Midoriya and Todoroki are cousins. This caused a controverse between TodoDeku's shippers and made only a small part of them to leave the ship thinking that the theory was true, without knowing that it was only a theory made by fans. The theory said that they were counsins because of the similarities between their family's quirks; Hisashi Midoriya's quirk is producing fire with the mouth while Enji Todoroki's quirk produces fire from body, which makes these quirks pretty similar.
On AO3, TodoDeku is currently the 3rd most written ship in the My Hero Academia tag. It is the most written ship for Todoroki and the second most written for Midoriya.
- TodoDeku posts on Tumblr
- 轟出 posts on Tumblr
- 出轟 posts on Tumblr
- TodoIzu posts on Tumblr
- Todoroki x Izuku posts on Tumblr
- TodoMido posts on Tumblr
- Todoroki x Midoriya posts on Tumblr
- TodoDekuEdit posts on Tumblr
- Todoroki x Deku posts on Tumblr
- Midoriya x Todoroki posts on Tumblr
- TDIZ posts on Tumblr
- TDDK posts on Tumblr
- Midoroki posts on Tumblr
- ShotoDeku posts on Tumblr
- Izuku and Shoto are portrayed as the sun (Midoriya) and the moon (Todoroki) in original art works.
- Both are also portrayed as the Christmas decorations: Todoroki is a candy cane which hangs from the Christmas tree (candy cane because of Todoroki's bicolor hair; red and white) and sometimes as a deer, and Deku is considered as the Christmas tree because of his messy green hair which has similarity with a tree.
- For the 5th anniversary of My Hero Academia, there were released celebratory videos. One of those videos features Todoroki and Midoriya named "I Want to Be Myself" with the song "Long Hope Phillia" in the background. Based on votes in Japan, the TodoDeku video is the most popular, seconded by the All Might music video and third place going to the BakuDeku video. On YouTube it is the 3rd most viewed after "Friends" (Bakusquad) and the KamiJirou music video.
- The official My Hero Academia Facebook account published a post featuring Todoroki staring at Midoriya during the scene in the Swimming Competition on the first episode of season 3 with the quote: "Find yourself someone who looks at you like Todoroki looks at Midoriya."
- TodoDeku has been featured on Tumblr's Fandometrics most reblogged ship list several times:
- An user from Twitter posted a TodoDeku painted mural in Bolivia (in Cochabamba's department), it's clearly shown both guys with rainbow colors in the background.
- After Horikoshi announced Moonroki and SunMido, the TodoDeku fandom came up with an idea; naming a star after them. There is now a binary star named Izuku & Shoto in the sky.
- For the 2019 Valentine's Fair at the Jump Shop in the Tokyo Station, they decorated the whole shop with images of Todoroki and Midoriya merchandises.
- If you clear the My Hero Academia ONE’S JUSTICE Mission Map 5, they'll reward you a TodoDeku's “Heart that Burns Red and Green” for clearing the mission with a team of just students. It also unlocks a Sports Festival gallery image.
- Todoroki and Midoriya share the same costume designer.
- In one of ☆オードリーAudrey☆'s posts, it's seen a Todoroki Fantasy AU BNHA Heroes card with a cute comment from Izuku; "The girls always say that Todoroki's really attractive, and indeed he does look like a Prince with this pose".
- In Todoroki's relationship chart, Midoriya tells him "It's your power, isn't it?", and Todoroki replies back with a "Thank you". 
- FANDOM had posted in Twitter Top ships of 2019 based on the Shipping Wiki Traffic, which post came along with a "You smash our hearts, TodoDeku" alongside with a punch and a red heart emoji.
- Todoroki never calls Midoriya for his hero name "Deku", instead of that, he calls him by his name.
- Bakugou Rescue Squad refers to the friendship between Izuku Midoriya, Shoto Todoroki, Eijiro Kirishima, Momo Yaoyorozu, and Tenya Iida
- Dekusquad refers to the friendship between Izuku Midoriya, Ochako Uraraka, Tenya Iida, Shoto Todoroki, and Tsuyu Asui
- Ghost Hunting Squad refers to the friendship between Izuku Midoriya, Shoto Todoroki, Hanta Sero, Tetsutetsu Tetsutetsu, and Eijiro Kirishima
- TodoBakuKiriDeku refers to the ship between Izuku Midoriya, Shoto Todoroki, Katsuki Bakugou, and Eijiro Kirishima
- TodoBakuDeku refers to the ship between Izuku Midoriya, Shoto Todoroki, and Katsuki Bakugou
- TodoDekuKiri refers to the ship between Izuku Midoriya, Shoto Todoroki, and Eijiro Kirishima
- TodoIiDeku refers to the ship between Izuku Midoriya, Shoto Todoroki, and Tenya Iida
- TodoIiDekuOcha refers to the ship between Izuku Midoriya, Shoto Todoroki, Tenya Iida, and Ochako Uraraka
- TodoIzuOcha refers to the ship between Izuku Midoriya, Shoto Todoroki and Ochako Uraraka
- Sharing something a little different today
- Cinema Today 2019.12.24
- Shoto as the moon
- Izuku as the sun
- "I Want to Be Myself"
- Post of My Hero Academia Facebook
- Fandometrics April 19 2019
- Top 100 ships of Tumblr's 2020 review
- TodoDeku's painted mural
- Izuka & Shoto Star
- Valentine's Day Fair
- Audrey's post
- Todoroki's relationship chart
- FANDOM post