Ichido Dake no Uta
Short sequel to the original story
Kimi ni Sasayaku Mirai
Starts with Senpai x Kouhai couple, but the senpai died in a plane crash. He came back in spirit to be with the Kouhai for one last time, which was sad, but he immediately re-incarnated into a younger Seme to be with the Uke. You could say he's the obsessive yandere type. Other stories as well.
Boku Dake No Kimi, Kimi Dake No Boku
Childhood friends with a bit of an age gap. Uke is very manly, a famous model who's chased by both men and women, but he will toss everyone and everything aside to be with his childhood hero, friend, and crush, who he thinks will never return his love.
Power of Love! (Prequel to Please Give Me!)
Prequel Friend x Friend’s single dad.
Please Give Me! (Sequel to Power of Love!)
Sequel Friend x Friend’s single dad
Hajishirazu Na Yoru
Age gaps in true Naomi Bohra fashion. One standout story is a master x servant
Dakishimetakunai
Standout story about an Assassin x Shinigami who falls for him and they both lose an eye in exchange for life together
Jashin to Shokugan
Evil god x Lonely human who held on to life because he wanted to be remembered and loved at least once
Koi Negawakuha
Two nekomata and their masters that they swear their lives to
Yurusareta Uta