@novacas Of course, it's canon. But Ootomo is not weird ass character at all, she's just conflicted between Ishigami, a good friend of her and Ishigami, the " horrible asshole stalker" that "ruined" Ootomo's friendship, romance and relationship. She might not hate Ishigami as much as everyone thought she would be, and was thinking to forgive him in the Sport Festival, but seeing Ishigami looked happy (he really deserved it) after "what he had done", she was pissed and dislike him more, to the point she got into a fight with Tsubame afterwards during the Graduation Arc.
Ootomo is not a bitch or whatever negative things people throw at her, she is just a poor
teenager girl who did 'terrible things' because she wasn't give all the proper information in the first place, and
not mature enough to handle things.