Warning! Spoilers ahead for My Hero Academia chapter 345!
The love triangle involving Ochako Uraraka, Himiko Toga and Deku is reaching its climax as the three characters finally confront each other in My Hero Academia. In chapter 345, All Might initiates his plan to separate the League of Villains members by pitting them off against certain heroes. Deku was originally meant to face the fully fused Shigaraki Tomura, but it looks like some sort of portal pulled him into an area with Himiko Toga and Ochako. While odd and a little too good to be true, it's truly serendipitous that the three of them will have to fight each other, considering their tumultuous past.
Himiko originally found herself forming such strong feelings for Ochako that the villain's Transform quirk not only assumed Ochako's form and voice as was normal, but even gained control of the hero's Zero Gravity quirk. Normally, Himiko's quirk compels her to drink the blood of those she admires due to an inherent urge to become them, and the stronger Himiko's feelings are for the person whose blood she sucks like a vampire, the more she can fully leverage her Transform quirk. And Ochako was the first person whose blood Himiko drank who allowed the villain to assume her quirk just because of how strongly Himiko felt about her. A main driver behind Himiko's draw towards Ochako is that the two are attracted in some way to Deku - and when Himiko first confessed how she felt to Ochako during the Paranormal Liberation War, she became overly excited about the prospect of being able to bond over their infatuation with Deku.
But Ochako didn't reciprocate those feelings. In fact, she completely spurned them to the point where Himiko was forced to leave in tears. Ochako was disgusted that Himiko leveraged her Zero Gravity quirk to hurt other people and completely refused to accept what Himiko had done and to return the villain's feelings. Himiko and Ochako haven't seen each other since that fateful day, so this confrontation is a truly momentous moment for the two of them, and fans are anxious to know how the two will react to each other.
In recent chapters, Ochako Uraraka did confess to Deku about her run-in with Himiko. But she was more concerned about how she sometimes finds herself trying to see things from Himiko's perspective and actively pushes away those feelings by putting herself in situations that cause her to see the devastation that Himiko and her comrades have caused to society. The fact that Deku - who serves as a partial catalyst to Himiko and Ochako's "relationship" - is there to witness them fight only fuels the situation further.
It's still odd, however, that All Might just decided to randomly pair off Ochako with Himiko, who is the one villain fans want to see Ochako fight against the most. It's possible that Ochako told higher-ups about her strange interaction with Himiko, but it's unlikely, and this would further dilute the aforementioned scene when Ochako confessed to Deku about her thoughts on Himiko. Another unanswered question in My Hero Academia is who or what transported Deku away from Shigaraki to witness this confrontation. Regardless, this upcoming battle between Ochako, Himiko and Deku is an altercation that fans have been thinking about for a long time - and it's finally here.