Because

Keisuke has taken on the debt of a junior and borrowed money from the black-market lender Suganuma. When the loan is due, Keisuke cannot return all the money. Suganuma proposes an alternative: instead of paying the interest, Keisuke must perform sexual acts with him. Reluctantly, Keisuke agrees, using his body to settle the debt.

As their arrangement continues, a complex relationship develops between them. Suganuma, initially cold and calculating, begins to see Keisuke in a new light. He becomes attracted to Keisuke's bravery and resilience in the face of a difficult situation. Meanwhile, Keisuke struggles with his feelings, caught between shame and an unexpected connection. Their dynamic shifts from a simple transaction to something deeper, blurring the lines between obligation and genuine emotion. Will their bond survive the terms of their deal?