Help me find the name of this manga

[falcofox]

It's a manga i read time ago so i don't have a picture.

It's about people trapped inside some kind of manor and have to play some games to get out. I remember the guy turns into a oni-like demon and have a child with the girl. At the end when they manage to find a exit the guy and the child cannot leave and the girl stays with them.

 

[shinpachi]

there are so many like that so i suggest you go to a big site or where you already read it before and choose a tag: game or traped /survival etc you would have more chances to find it that way