Headscratchers / Maria no Danzai

• Okay, so, first of all, I still don't get how Okaya suspects the culprit who killed Kowase and Shikimi is one of his dead victim's parents. Sure he is right, but how can he believe it may be the parents when he and his gang framed Kiritaka's death as a suicide case due to his parents' "abuse"? Logically, said parents would blame themselves instead of the possibility that he died for other reasons. How does he know that the parent may be aware of their son's horrific bullying? Besides, like he said to Kinugawa, they have a lot of enemies. One plausible reason why Okaya suspects Kiritaka's parents may be because Kiritaka is the only known victim to be killed because of them. However, any enemy can be willing to kill the gang, even if they did not have someone they love (indirectly) murdered in their hands. The killer can also be another of their victims who has enough of a valid reason to want them dying, which is why his conclusion with the knowledge he has now doesn't make sense to me.
  • If you're making the assumption that two of your group are gone and that it's related, then you need to think of a motive as to why, which leads to it being revenge for someone they bullied. That someone was able to take out two of them without leaving any signs would suggest a level of competence and means beyond what one of their victims could muster, so then it becomes who would hate them enough to want them dead, which leaves the one person they killed. It requires several assumptions but isn't much of a logical leap.
• Another question I have is how does the remaining bullies know that Kowase and Shikimi are dead when these two are considered missing under the police investigation?
  • One of their comrades vanishing without a trace is a concidence. Two of them doing it in relatively short time is a pattern. Once you assume thay foul play is involved, it becomes unlikely that either are still alive.
• I'm curious to why Maria doesn't tell Taiichiro about their son's bullying and the fact the suicide note online were fake? Right now, it's all a mystery, but from what I've seen she wanted to punish them herself. Was it because she didn't want to jeopardize Taiichiro's job as an inspector, or that he would have tried to stop her, or that she blames him for not noticing his son's pain, or a mix of them? She clearly didn't plan that her last name was going to be noticed by him, and her face when she saw him in the nightclub was of surprise. At the very least, I think she doesn't want to hurt him, but if he's an obstacle, she's going to have done something about her ex-husband.
  • Truth in Television / Genius Bonus. The Japanese justice system is infamously lenient on crimes commited by minors, read on the 40-day torture and murder of Junko Furuta (or don't and sleep better). That is even more of a issue when you take into account the implication that Okaya's family is rich/influential, and Okaya has tailored a reputation as a kind-hearted model student. It makes sense for Maria to not involve Taiichiro, since he would likely try to get the police and courts involved, which would amount to nothing and defeat the whole point of what Maria's trying to achieve. Also, while Taiichiro is definitively a good man who loved his wife and son, he was also a pretty absent father and husband. Maria might think he wouldn't be of help if he knew, or might even see allowing him to think his son died of suicide because of his neglect as her own "punishment" towards her ex-husband.