In order to escape from the marriage of convenience, it was the Miasma Forest where she got lost --- The heroine who was helped by a witch boy with a beautiful face and decided to live together. A cool boy spends a calm time while being healed by a carefree smile that suddenly appears ... Starting with a certain incident, she becomes aware of the boy's "true appearance". "It's hard to suppress at night --- I'm ugly?" By the forbidden technique, a boy who has a monster, Hydra as a part of himself, spins while living a time that seems to be eternal. "This monster is hungry and now seems to be dying for a woman's flesh." Countless Hydras (tentacles) entangle the heroine's body, snarl and groping. The boy asks the heroine while suppressing his lust for her, "Do you want to stay or go back... I hate to force, so choose". What is the ending that the heroine chooses--?