"I've come to eat you." So softly utters the mermaid Shiori, as she emerges from the sea and takes high school girl Hinako by the hand. Hinako lives alone in a town by the sea, and possesses an unusually delicious body that is irresistible to nearby monsters. To ensure that she matures to the best condition, Shiori seeks to protect Hinako-all so that someday, she can devour every piece of her. What will become of Hinako's feelings as this looming unjust death closes in on her...?