Halloween engage - daiya no ace dj
Synopsis: Boy dresses as an incubus for a halloween costume, but won't f*ck his friend. Then, he does. Because turns out he actually IS an incubus. Then the guy he f*cks claims to be a priest, and later claims to actually be a demon. The end. Pretty much just yaoi, no bl. Not my thing at all, but I'm sure that if it was your thing, you might like it.
Asmodian's Contract
So great, omg. Ok, so a horrid princess dies and makes a contract with a demon to keep living in her place, so that revenge can be had on her step mother who poisoned her (the step mum did this partially because she wanted her son to inherit the throne, and partially because the horrid OG FL slapped the innocent step-mum's daughter). So, the demon does and begins rekindling the FL's rep, while assuming the position of leader of the 4th knights, and befriends one of the country's leading swordsmen and his friend. The swordsman I assume is the love interest
Fuin maou wa mederaretai