Mai Mutsuki is an attractive young woman with a busty physique. She is an old friend of Masaki Morikawa, reuniting with him unexpectedly during a chance encounter while he pursues outstanding debts owed to his family.

Her father carries a significant debt to the Morikawa family. Mai's pre-existing affectionate relationship with Masaki distinguishes her from other debtors' families and facilitates the rapid initiation of a physical relationship between them after the debt revelation and their reunion.

Initially, Mai does not know about Masaki's concurrent exploitation of another debtor's daughter, Mizuki Kanna. Information about her family beyond the debt, occupation, education, specific personality traits outside interactions with Masaki, or her role in potential sequels or expanded narratives is not included.