Kaori often brings her boyfriend, Jun, home because she's short on dating money. Jun is welcomed by her mother, Saki. They seem like a happy couple and mother-daughter duo, but in reality, Jun and Saki have been secretly having an affair behind Kaori's back. They continue their clandestine relationship, careful not to be caught, but one day, Kaori stumbles upon their secret when she peeks at Jun's phone and realizes what's going on...