Mamotte Agemasu! (yamato Nase)
It's not tagged as a shota, but I feel like it is. A 1st year high school student with an adult male that's mid 20s to early 30s.
I'm No Match For Him
It got a little boring for me about half-way through. A nice ending, but I would have liked it better if it showed him graduating.
Keiichirou Does Nurse Cosplay With A Perverted Teacher In The Student Council Room!
Before I Close My Eyes
Multiple stories, most are connected with each other with the couples.
The Alpha's Circumstances
I would have liked this story much more if it wasn't for the fact that he cheated on his boyfriend. I've read stories where alphas aren't attracted to omegas till that one special one comes around and vice-versa, and it would have been a cute smutty story if it went that way. But it didn't so its meh with great sex scenes.
Wakadanna ni Goyoujin
I only liked the first story. The rest were filled with rape manipulation, and 30 something with high schooler.
The Lovesick Flower Buds Waiting for Spring