Second MIYAMOTO Kano, NAONO Bohra, and YONEDA Kou for the strength of their stories, though they all do some school life settings. Yoneda-sensei in fact made her name doing Katekyo Hitman Reborn! doujinshi, which is of course about 14-year-old schoolboys (who happen to also go back and forth between being 24-y-o, but that's beside the point ).
First, I would like to second the work of YONEDA Kou. And - It's understandable for me, that many Yaoi seem to be quite unrealistic and the relationships simply too rushed- Fortunately there are still some authors, which have in my eyes been able to develop well-balanced stories, even if some of their works revolve around students, like ...
________________ "It's like love is a bonus in your life. Even without it, I'm just fine. I don't feel like pointlessly searching for it. You don't have to make yourself unhappy." (Ookami Shoujo to Kuro Ouji)
"Why does it rain?" - "To create drama." (Drops (Andou Yuki))