
maybe in his past life, Gaku was actually like his school bully or something...
Or maybe it's like people are saying and Gaku died and the MC got memory loss. Maybe the point the MC went back to is actually when Gaku originally died and there was an accident that killed Gaku and is where he hurt his leg. In this accident maybe he lost his memories which is why he originally didn't remember Gaku. So they were given a second chance to see what would've happened if Gaku had lived from that moment. Since in this timeline, Gaku is still alive, the memories the MC had are corrupted and he doesn't remember Gaku dying.
Or maybe it's like some Your Name shit and Gaku is actually a highschooler in present day that's somehow in the past who knows lol.
I don't even like the manga that much but I need to know what happens nowww

the story makes so much more sense now we know the backstory. People were complaining about him so much about being so overprotective but it was for a very good reason. Obviously, he is going to be overprotective of his dead best friend's/(man he loved?) daughter and want her life to be perfect even if it isn't in her best interest. Despite how cheesy and silly this story is it's actually so heartwarming and also really well-paced
this has On or Off vibes I'm here for it