So that's it. Chako stabbed her dad in the arm, mom finally opened her eyes and now they're gonna try and start again.
Gen's letter was short, but necessary. It was also the last dark epiphany Reiji got, one that is making him realize he is losing everything although that's what he wanted that was tying him to this life. I think deep down, Reiji was wanting the old Gen from his childhood to return, but with that letter, he realized he already lost his best friend.
Have this feeling Chako picked the implication of what Reiji meant with "staying in this town forever" and that's why she didn't attempt to give it more afterthoughts, by saying he'll stay in this town, he meant he will rest in peace there
Considering Yuri's concern about Reiji's plan, and Reiji wanting her help after he kills Mao, one of these 2 things may happen...
1) either Mao's sob story and Reiji gets cold feet/remembers what Nagi said about people living the lives they deserve and considers killing Mao is not wotrth staining his hands because he is already fucking dead, but Yuri, obsessed with marrying Abyss-kun, kills him
2) Reiji actually kills him.
In both cases, Yuri is also fucked. She is not gonna obey any of Reiji's orders, will try to be one step ahead of him, and it seems those shoes at the end of the chapter are actually hers. Until the very last minute, she's gonna cling onto her boytoy. Reiji's patience with his former teacher will run outvery quickly and, before a double suicide, we may have a double murder case.