Mouryou no Nie - Season 1

Derived from the Tinker Bell erotic game. In an ancient conflict centuries past, humanity emerged victorious over monstrous foes, imprisoning them deep within mountain seals. Hayato, Chihiro, and Suzuna dedicate themselves to containing evil creatures, though they themselves are monsters who seek peaceful coexistence with humans. Upon learning the ancient seals are weakening and the imprisoned monsters may soon break free, the trio resolves to journey to the site to prevent this resurgence.