Yukiya Ayase is a kind-hearted and trusting college student who becomes the main focus of the story. Unfortunately, his only living relative, Tetsuo, is exposed as a dishonest man when he attempts to auction off Ayase to pay off his debts and earn a large sum of money. Somuku Kanou, a wealthy loan shark with a difficult personality, sees an opportunity to acquire Ayase for a mind-boggling 1.2 billion. Despite being unable to recall their previous interactions, Kanou ultimately saves Ayase from danger. However, Ayase is required to engage in sexual relations with Kanou every time in order to remain in his care, for which he is paid 500,000 as compensation. At first repulsed by the idea, their relationship evolves into an unbreakable bond that proves to be priceless.