Ore no Kirai na Senpai
Sano is very jealous of his rival's popularity with women. However, when he sees Azuma getting it on with the girl he has a crush on he somehow ends up masturbating with his rival instead? I just love how by the end of this story he's so proud when people say how hot/cool/amazing his boyfriend is <3<3<3
Caste Heaven
Another favorite. It's a fucked up story at the start (and at the end) but its SO GOOD. Azusa used to be the king of the classroom as decided by the caste game the school plays, but in his second year he ends up being the slave. Which is mostly just the personal sex slave to the current king of his class. Also, all the other stories and pairs in here are amazing!
Yarichin ☆ Bitch Club
Transfer student accidentally joins the all boy school's sex club and now has to either lose his virginity or get gang banged. Hilarious. I loved every second
Goshujinsama to wa Iwasemasen!
Cute little story about a transfer student who gets asked to the master of the school's No. 1 delinquent
Boku wa Kimi no Iinari
Starts off as a smutty "I saw you masturbate so I'm gonna continue to watch" into a really wholesome love
Mihanada Pectolite
Two nerdy boys battle it out for the top student at their school. However, once the seme gets noisy into the uke's life they realize that there might be more there than a rivalry. Featuring cute younger siblings that are twins
Batsu Game (Conro)
A guy is dared to kiss a stranger so he does, turns out the guy he kissed was his horny senpai that's looking for some action. Uke is quiet loner type in the classroom but a freak in the sheets
Gosan no Heart
A playboy, Miki, sees his classmate, Udou, unable to get a girl to give up on him. So Miki jumps into help by saying that they're already dating. So they actually date. Adorable stories (also same author as caste heaven and they characters are less extreme versions of those two)
Bouai Friendship
A student who is overlooked by every and called ghost senpai is finally seen by a kouhai. Sure, being seen means that he is essentially raped in a classroom, but he's very lonely so let's the sex friendship continue
Junketsu Drop