Morisaki Hiroto is working away from his family. One day, he receives a phone call. It's his wife, who tells him that their daughter, Runa, is coming to visit him during her long vacation. However, his wife has other plans and can't make it. "Take care of Runa during the vacation. She'll be there soon," she says, before hanging up the phone. Hiroto is left with no way to escape the sudden visit. While he's waiting, the doorbell rings, and he ends up welcoming Runa. Since he last saw his daughter, Runa, she has grown into a plump and sexy body, while still retaining her childlike innocence. Or rather, the imbalance between her baby face and body makes her look even more "lewd." Hiroto somehow manages to resist the idea that his daughter has a sexy aura about her, though it may just be his imagination. One day, when Hiroto returns from work, he finds that Runa has unearthed his carefully hidden collection of exquisite SM toys. His daughter approached him, deliberately asking him how to use them. With everything about Hiroto falling apart, he falls deeper and deeper together with his daughter Runa, like a wolf caught in a sheep's trap.