Jingai-san no Yome
High school student Tomari is told one day that he's to be the wife of a strange creature called Kanenogi. Turns out there's a lot of these marriages with non-humans going around their school, and all the couples are super cute.
Kami Tori Yawa
A Japanese mountain god (later called Water Lily) finds an injured man on his mountain treating a deer's injury and begrudgingly takes him back to his shrine and heals him. The man, Kyouya, agrees to tell Water Lily about the city in return, and ends up getting physically intimate with Water Lily, only to steal one of his horns right after the act, rendering him powerless. Water Lily has no choice but to go to the city with Kyouya, but he finds that Kyouya takes good care of him and is so kind, that he doesn't mind that Kyouya took his horn, until he learns Kyouya only did it to give him to the emperor. I think Water Lily is an interesting character, and given that he's not human, the way he perceives Kyouya is fascinating too. Trigger warnings: kidnapping, noncon.
Bocchi Kaibutsu to Moumoku Shoujo
The monster Heath has always lived alone, until one day she met a sweet blind girl named Lily who gave her a name. Though the relationship started out with some deception on Heath's part, the two fell in love and started living together. The story is mostly slice of life as they have cute moments together and get to know other friends and family, gradually opening up Heath's world. Trigger warning: discrimination.
Monster and the Beast