Yeah... i dont like it.
He had a bad highschool... but what about the others? Tô me they all had great lives.
This is pure selfish behavior from MC... this would work out more if he at first encont3r a gloomy girl that was on his class like him... and she said that she had a crush on him at The time... and going home he was thinking about her and how the two of them could had a highschool love life, but better not cry over spilled Milk... lets try our best now with her, she was still gloomy but had her charm.
Now he dies go tô the pass and makes his mission tô have the best highschool romance with her... doing his glow up and falling in love with her just because in the future she was the only woman that apreciate him.
Tô me she would change a little being more cheerful but very insecure expecially because MC would love bomb the shit out of her... you could even have a menhera arc.