The first two chapters give a vibe that maybe the girl already passed on long before the actual taking place or it’s been a long time since she left him but the guy (seme) is lying to the uke. My opinion is that the girl never died, she left him the brother stayed because he always loved the Uke and now the uke is sleeping walking or has memory lost due to an accident that happened to him AFTER the girlfriend left him so he thinks that they still together but actually it’s been like years and the uke and seme become Fbf but the uke cant remembers it