Basically I thought I had clicked on the right option, but now, 20h in the game, I now realised it was a mistake. 
I know there is no way to change that, but in the future, is there talk of an update that would allow use to activate certain route ? 

I reallyt don't want to redo everything again

what choice

Didn't befriended Adrian

no, decisions are final. For befriending adrian you can share one of the possible girls with him. If sharing Alice, you also need to do gaming night 3 times.

I don't see a problem in playing again and trying out other paths not taken before, this brings a replayability that attracts me.

Yeah I did play again, but to each their own. I don't like doing the same story again. I only really did it because I wanted to see what could the Japan trip offer (not much)