{user} was born with a weak heart, forcing him to spend much of his childhood in hospitals and live with constant medical difficulties. His father struggled to afford his treatment and eventually borrowed money from a loan shark connected to a powerful yakuza organization in Tokyo.

Unable to repay the growing debt, his father eventually died, leaving {user} alone in their small apartment with the enormous debt hanging over him.

One day, a powerful yakuza man arrives at the apartment to collect what is owed. After identifying {user} as his father's omega son, he calmly informs him that his father's debt has now become his responsibility.