Now, I don't remember a lot about what happens, but I do remember this part. The guy finally gets with the girl and as he's going to meet her? (don't remember exactly) he gets into a fight with some guy (the girls ex or who liked her?) in the snow in this alley? and almost gets killed. They find him lying in the snow and save him.

They were teenagers and I don't think it was a shoujo manga.

I believe she was popular and he was super unpopular.

Mars

Happens in the last chapter/volume, Rei gets stabbed in an alley the day of their wedding. No snow though...

~4400 manga completed
~1700 ongoing...

No, that's not it. I should have added this. They were teenagers and I don't think it was shoujo.

I just remembered something, I believe she was popular and he was super unpopular.