I don't think Seiichi can lie and claim he did it when the victim (his cousin) can testify and say the mother did it (which we saw he is plenty capable to do). Sooo I want to believe he will go ahead and say the truth? I mean his mom told him he doesnt have to lie anymore...
I felt kinda bad for the dad tbh. He seems like a regular ass dude that just wanted a normal family but then turns out his wife is batshit crazy and tried to kill his nephew and now all this. Idk man is just sad.
That's a pro move right there, busting a nut while stressed and fucked up. 10/10 would recommend if your ok with post-nut clarity that rivals that of Einstein's IQ