True End of Those Days
A slice of life story about the Rei, the demon king, and Aoi Yamato, a hero who was summoned to defeat the demons, who have since married. The chapters show Rei trying his best to learn how to be a housewife while Aoi goes from seeing this as a marriage in name only to actually caring about his partner. Very cute. Trigger warning: cheating.
Eat Me Up, My Husband
Former delinquent Mizuki fell in love with his husband, a child who comforted him after a fight, despite the twelve year age gap. Now, after a year of marriage, the two are lovey-dovey husbands, but Mizuki worries their sex life has cooled off, so he's trying his best to seduce Kotaro all over again. Meanwhile, Kotaro worries that Mizuki only wants him for his dick, so he's determined to make Mizuki love him without sex. A silly misunderstanding for a couple that is very much in love. No trigger warnings.
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.
Hanazono No Kioku
Author Yuu gets drunk one night and wakes up with a tattoo ring, but when he finds his partner, he learns that the young man, Chris, is taking their "marriage" much more seriously. Despite Chris's issues, Yuu accepts him into his life until one day his mental instabilities become too much. Chris leaves, but Yuu decides to track him down, where he learns of Chris's past and his unexpected connection to Yuu's books. Also includes a oneshot about a black cat and his overly attached owner. Trigger warnings: threat of violence, drug addiction.
Risou No Himo Seikatsu (novel)
Zenjirou is a corporate slave who gets summoned to another world by the queen, Aura, a sexy lady who offers him the perfect, responsibility-free life of his dreams as her husband.
Papa x Papa - α To Ω De Sorezore Yattemasu