Momo and Karin, the well-bred sisters from a wealthy family, were suddenly orphaned when their parents died in an accident. They were taken in by their uncle's house. Despite their nervousness, they comforted each other as they arrived at their uncle's house. The uncle seemed kind, and Momo and Karin felt relieved as they fell asleep. However, the next day, they woke up to find themselves naked with handcuffs on. Their uncle, with a sinister smile, revealed his intense hatred for their father. He declared that from now on, they would compete in sexual servitude to prove their love for him as his "daughter." The loser would be expelled without any family ties.
