[Dante of the Inferno]

Originally Posted by Kantoku

But...

Spoiler for Keiichi in Onikakushi-hen:

I probably should know this since I've read it many times, but what exactly triggered the parasite in Keiichi to hit L3 when he came back to the city? Unless the source of the stress is never known and it may be because of something while he was at the funeral. People can't hear Hanyuu unless they're at least L3, right? Even in other arcs where he left and came back, he was not in L3 state but only in Onikakushi-hen he is.

Spoiler for Explanation:

We talk a lot about "triggers" when we refer to certain characters becoming unstable due to Hinamizawa Syndrome, but I treat Keiichi's case differently. Of course, it all starts when Tomitake comments on the murder at the construction site, but of course that alone isn't enough. It's actually this whole rapid succession of events that triggers Keiichi. Tomitake's comment, Keiichi's induction into The Club, Keiichi finding the newspaper article, Watanagashi, Miyo explaining Oyashiro's Curse, Miyo and Tomitake's deaths, his friends' behavior, and Oishi's involvement all take place over 5-6 days. That's a lot of unsettling information coming at him that hits increasing closer to home with each passing day. As such, I think that this culmination of events is what set Keiichi off, manifesting during his questioning by Rena.