I think that one moment where Dazai realizes that his friendship with Chuuya means so much to him now that he doesn’t want to ruin it in any way. Before Chuuya did what he did in ch15(?) Dazai felt like they could go on being friends if nothing disturbed their friendship, that includes romance and also a certain conversation he overheard between Chuuya and his dad.👀 But yeah, I think him feeling like that is the kind of foundation that any relationship should start with. When someone has become so important to you that you don’t care how, you just want to keep them in your life and you’re afraid to lose them.