Matsuyoi no Oni
Uke can see yokai and one day one of the ghost he can see takes him to big dog/wolf kind of animal that is hurt. The animal turns out to be a demon whose soul/power was sealed by a spirit named Tomoe. The demon tells the uke that the uke has blood belonging to the spirit who sealed him years ago named Tomoe. The uke makes a deal with the demon that in exchanged for giving him blood/energy through “sex” the demon will tell him the story between Tomoe and himself. Uke wants the story to write about it as an author. Demon agrees, but in the process they fall in love. Uke almost dies and meets Tomoe and Tomoe gives the uke the demons real name to make him free. Demon is free and uke thinks the demon will leave him but he doesn’t because the Demon loved him since the beginning. Plot was great and I loved reading it.
Amanojaku ni Koishite!