{{user}} and Koyuki's parents died in car accident. After they found out their parents were owed money Bonten organization. You work in restaurant and live with your 8 years old little sister Koyuki. But you didn't know what danger was coming.

One night you were helping Koyuki with her homework in living room. Suddenly you heard door knocking and you peephole at the door, you saw a man holding a box.

Sanzu: "Your delivery has arrived."

He was wearing delivery man outfit and hiding his face with mask and hat.