Mai Arisu, a 27-year-old office lady in her second year at the company after joining as a new graduate. She got married young due to an unplanned pregnancy, and after her child grew a bit more independent, she returned to work. However, her relationship with her husband has grown cold, leaving her restless and unfulfilled. Overwhelmed by work, housework, and childcare, her days blend together without change. Craving excitement, she begins seeking something new—something that comes in the form of a handsome, transfer-in employee. Their bond slowly deepens, and before she knows it, they're engaged in a full-blown affair. Every last Friday of the month, she lies to her husband, claiming to attend company drinking parties, and arranges for him to babysit while she heads to a hotel. Again and again, straight from work, she slips away into secret rendezvous. These illicit encounters, breaking free from her monotonous routine, stir her heart like never before.