Momo and Katsuki hardly ever interact due to their different group of friends and because their personalities do not make it easy for them to get closer. Momo is an organized person, calm, quiet, enjoys working in a team and helping others. Whereas Katsuki is the complete opposite of her⁚ messy, restless, loud and rarely enjoys teamwork or making friends.
However, Momo can have rare moments of anger very similar to the ones Katsuki has daily. As when Mineta and Denki tricked her and the other girls into wearing cheerleading outfits at the Sports Festival, Momo gave a rare cry of rage (something no other girl in class did) and is also capable of commanding or screaming outrageously when motivating others to act as did in the Paranormal Liberation War, which is why Momo can be quite similar to Katsuki in times of anger or need.
Unlike their other classmates, Momo appears relatively unimpressed upon seeing Katsuki’s incredulous throw of 705 meters (in the quirk apprehension tests), and simply stares boredly, as if it is nothing more than a daily feat to her. This gives the early impression that she doesn’t seem to find Katsuki any more exceptional than anyone else, which proves to be rather defining in later times.
During Katsuki (and Tenya’s) Battle Trial against the team of Izuku and Ochako, During Katsuki’s battle trial (with Tenya, against Ochako and Izuku), Momo comments that his feint attacks are impressive, as they require an extreme amount of precision, and adds that he demonstrated an incredible control over his quirk, alongside calculating the physics in which he moved at. She is the only one to manage to deduce this. At the end of the fight, she looks rather disappointed in Katsuki's behavior compared to the disturbance of the others.
After Katsuki, Izuku, Tenya and Ochako are gathered, Momo gives commentary on the fight, and what each student did wrong. She gives an entire analysis on Katsuki, rather than just calling him the usual “reckless”, and seems to truly hit every sensitive spot in Katsuki’s heart. This only worsens when she is revealed to have entered U.A through recommendation alongside being the first admitted to U.A. This is the first time Katsuki realizes that there are others, including Momo that are more capable- and even more worthy of becoming no. 1 than him, which is a defining point in his early (character) development.
On the bus ride to the USJ, Katsuki is angered by Denki stating that he has the personality of a “steamed turd”. As he yells, Momo holds a repulsed hand over her mouth, and complains to Ochako about the vulgarity of his language. In the obstacle course of the Sports Festival, Momo along with Katsuki and other students are able to avoid Shoto's ice attack to continue in the competence.
Soon after Katsuki's kidnapping by the League of Villains in the Forest Camp, Class 1-A makes a visit to their fellow classmates who were injured during the camp, and were thus charged into a hospital. During the visit, Eijiro becomes emotional and (loudly) expresses the guilt he feels over the loss of Katsuki, and not being able to fight for him before suggesting that the class rescue him themselves. Tenya immediately shuts this idea down due to the complete idiotic nature of it. However, that night, the group of Eijiro, Izuku, Shoto, and Momo, who’d managed to stick a tracker on the body of her previous Nomu attacker (Tenya joins them soon after, albeit hesitantly). Momo aids the final act of bringing Katsuki to safety, and is with him as he is brought to the police for questioning/aid. It is quite notable that Momo, who hails from a noble family of heroes would defy orders from her greaters to assist bringing Katsuki to safety, despite the risk it would hold to her (future) career.
After Class 1-A chooses to do a concert to perform at the School Festival, Kyoka decides four members of the class to be in the band with her, choosing Katsuki and Momo (along with Fumikage and Denki) play the respective instruments of drum-set and keyboard. In preparations for the concert, Katsuki seems to have notably more respect, and a sense of closeness towards his bandmates, including Momo. Post concert, Momo can be seen cheering on Katsuki in the obstacle course that was at the Festival.
In the Paranormal Liberation War, Katsuki and Momo do not interact directly and are not shown side by side (since they are both in different areas during their respective battles). However, both at some point end up making hasty plans during a moment of crisis and ended up guiding different Heroes to face the most powerful Villains of the League of Villains, Tomura and Gigantomachia. Katsuki is at the center of the battlefield during the War and momentarily guides some Professional Heroes to confront Tomura when Izuku is in danger and they cannot defeat the Villain. While Momo is near the Gunga Mountain Villa area and ends up leading the students of her Class and those of Class 1-B to face Gigantomachia to put anesthetic in his mouth to put him to sleep and defeat him.
Following the events of the Paranormal Liberation War and Izuku's escape from U.A. High School, Class 1-A decides to go find him. After Katsuki manages to defeat Dictator (a prison fugitive villain) while knocking him unconscious, Momo creates handcuffs with her Quirk to chain the Villain and congratulates Katsuki, but she accidentally speaks to him by his last name instead of his hero name: Dynamight, causing Katsuki to correct her and Momo apologizes for her mistake.
When they finally bring Izuku back to U.A., Class 1-A is training among themselves in the courtyards of U.A. to improve its skills. Denki talks to Minoru about how with Tomura and All For One currently weakened the fight should be easier for the Heroes, but Katsuki tells them three reasons why they are wrong. Katsuki says that even after being able to locate the Villains' hideouts, the Heroes were never able to locate All For One on their own. Momo interrupts him by saying point two which is that Tomura was incomplete in the previous battle, and Katsuki ends his words by saying that the last point is that the villains will be the ones to decide when the battle begins (indirectly showing that Katsuki and Momo are capable of finish each other's words perfectly).
Due to high competition from either character’s (most widely considered) “canon” ships (KiriBaku/TodoMomo), MomoBaku is not a particularly popular pairing and remains a “rare-pair”, although its twist on the typical “good girl/bad boy” trope still manages to reel in fans in a similar manner to Kacchako. Momo holds a notably respectable stance in heroics thanks to her background, which seems to have brought her a sort of respect from Katsuki from the start that did not go un-missed by fans of either character.
Additionally, in a joking manner, fans have stated that Momo could act in the “dominant” role of their relationship as opposed to the headstrong Katsuki, although this does, of course, spark genuine interest in fans of such a concept. As well as this, Momo has also proven to be one that could drag Katsuki down from his “high horse” in a way without shattering his inflated heart. Noted by fans, two are those who tutor their ‘less academically gifted’ classmates as well, although Momo does a study group while Katsuki just tutors Eijiro.
BakuMomo has about 400 fics on AO3.
- Katsuki and Momo are roughly the same height; Momo is 1 centimeter taller than Katsuki (Momo = 173 cm, Katsuki = 172 cm).
- The two rank in the top three in the class when it comes to intelligence, Momo is no. 1, while Katsuki is no. 3 (just behind Tenya).
- Both are considered to be amongst the most (physically) gorgeous in their class.
- Momo and Katsuki are both known to have past interest in music aside from hero work, as shown by their respective interests in keyboard and drumming. Additionally, both these instruments are counted as ‘percussion’.
- In a horikoshi drawing for Volume 4 of the Smash!! manga, some of the students from Class 1-A were drawn together in a Character Swap and Momo and Katsuki were shown being each other while wearing each other's Hero costumes.