They don't have lots of interactions together because Ochako tends to spend more with Tsuyu Asui and other of her classmates rather more than Shoto, meanwhile she uses to interact more with Izuku when she's with him. However, the three of them do share a moment in the My Hero Academia: Two Heroes movie.
Meanwhile Ochako was dealing with some of Wolfram's bots and after being saved by Katsuki, Todoroki asks Ochako if she was fine, after Ochako confirmed Shouto's question, she pointed him out that Izuku and Melissa were on troubles in midair. Shouto then goes for rescue as he used his fire for making warm air to the fan where Izuku and Melissa were going to crash, impulsing them to the opposite side saving them and also giving them a hand so Midoriya and Melissa could react David and Wolfram. As they were saved by Shouto's quirk, Midoriya thanked him internally.
Despite of the three not interacting equally, something that they share is that they're all part of the Dekusquad, along with their other friends Iida, and Tsuyu, with sometimes Bakugo. Ochako and Todoroki are also part of Dekubowl, as both were helped and saved by Izuku itself.
TodoIzuOcha is a popular polyship among the fans who ship IzuOcha and TodoDeku at the same time, and had created the ship. However, the ship itself isn't as known as TodoBakuDeku or HimiTsuChako, this is because of the constant fights between both IzuOcha and TodoDeku shippers. The ship can be portrayed as a one-sided crush on both Shouto and Ochako, though Ochako's crush is canon while Todoroki's crush on Izuku isn't confirmed, and hasn't shown any signs of it yet.
Some fanarts could portray Ochako accepting Todoroki's crush on Izuku and that the two of them would be whether good friends as both having the same love interest. In other fan arts Ochako can be shown jealous on Todoroki for being the most cloest to Midoriya, making them as love rivals. However the ship itself doesn't really have big fanbases but known ones such as Twitter and Tumblr.
Ochako, Todoroki, and Izuku only share one trait, with the three being "pure" according to fans, and that they would rather ship TodoIzuOcha in the cute, soft, and fluffy way rather than a sexual and abusive one. Shouto can be pure, because of his innocent way of thinking, taking Mt. Lady's interview as an example when she told Shouto that his smile would kill lots of girls, and Shouto took it way too serious, being worried that his smile would, literally, kill all of the girls around the world. Ochako is also pure because, besides of her cute design, her behavior and innocent crush on Izuku, though she sometimes can have a scary and "badass" side taking Bakugo vs Ochako's fight as an example. Finally, with Izuku, according to fans he's a pureful guy who, even being a grown kid, he was still being and looking like a baby and they would still find Izuku's admiration for All Might as cute, and sometimes they compare him with a cinnamon roll or a broccoli.
On AO3 the ship has 101 fics on the romantic side, while it has 25 fics in the gen side.
- TodoIzuOcha posts on Tumblr
- TodoDekuOcha posts on Tumblr
- TodoChakoDeku posts on Tumblr
- Todoroki x Midoriya x Uraraka posts on Tumblr
- They're sometimes portrayed together in canon artworks.
- IzuOcha refers to the ship between Izuku Midoriya and Ochako Uraraka
- TodoChako refers to the ship between Ochako Uraraka and Shoto Todoroki
- TodoDeku refers to the ship between Todoroki and Izuku Midoriya