Akira is afraid to losing the Satsuki-bowl to sensei, without even knowing Komachi is the real last boss.
My guess is Komachi just does everything she’s told, so she won’t necessarily try to help the one being bullied. That girl just finds living to be pointless and it’s not like Satsuki hasn’t broken her trust before. And don’t even think there’s any workaround here since her death is kinda what started all these killings.