@gronkle @Ominous @Fuko @Nigilith
Guys Kei is not killing his dad, he was gonna kill him at first, but mid conversation Kei decided that he was gonna turn him in rather than killing him, so yes he will incriminate him by revealing the truth, Kei will follow the plan.
When Kei said "The worst" at first glance that seems like Kei is talking about his dad, but no, he is talking about himself, because that is immediately followed by "I just can't bring myself to hate you!".
The moment the father heard Kei say that, he tried to make up some bullshit excuse "oh he still likes me, i can still bullshit my way out of this by blaming that guy, and cover things up", but Kei stopped him immediately, he told him to not even try, and to at least keep some dignity, then he says that he will turn them all in, and if he wants to stop him he better give Kei out to his friends, that means Kei is prepared to end as a sex slave for the sake of stopping them, it is his resolution, when he says this he affirm that he is still "Keichiro Kai" while holding back his knife.
He is no longer trying to kill his father, he still calls him dad, but that doesn't means he forgives him, not at all, he is going with the plan, and the first one that will be exposed will be his father.
Now the question is, the resignation of his father as a father, is him admitting defeat or a declaration of war?