Homeless, cold, and a virgin, Klayden lives on the outskirts of a prospering fishing village, though he feels none of that prosperity, as his shelter is burnt down, the rain pours only after the shelter is destroyed, and nobody offers him a lifeline on his final day.

Fortunately for Klayden, a mysterious benefactor saves him, and he wakes up in a mansion full of monster girls. From there, he discovers an entire underground world full of creatures hiding from the human eye.