Responses
That's assuming that Ijima died before being investigated. He could have let Maria's name slip at any time, especially considering how Shikimi disappeared right after she told Ijima to do something about her. I feel like Maria is in more danger now until she finds out who killed Ijima because depending on who it was that killed him, they could have some connection with her and link her to Shikimi's disappearance.
Isn't it good for her that Ijima is dead cause he was a liability to her anyway, and it seems like the violent kid killed him so it will most likely be pinned on him. Even if it all traces back to Shikimi's disappearance, it would just seem like Ijima was the one who killed her, so Sensei's tracks are covered temporarily right? I mean since she needs to kill all of them, all of them disappearing will look suspicious anyway (they already have a team formed for two kids disappearances and the kid ringleader of the group is already on to her) and there is no fixing or accounting for that imo, but having a cover for the unexpected variable (Ijima) that could have exposed her sooner still works in her favor. Right? Another issue is the dad getting in the way but I like the theory of them being in kahoots. But also, I feel like he'll just let her go and won't actually help er so...