Nanako is a married woman living an ordinary life. One day, her plumbing breaks down, so she calls for a repairman. The technician who arrives is a quiet, aloof young man named Mitsuru Kawase. He explains he’s come to the city to apprentice at his family’s construction company. Nanako asks him to fix the pipes, and though he successfully resolves the issue, a sudden burst of water causes chaos, leaving Mitsuru flustered and scrambling. Though hardworking, he’s prone to clumsy mistakes. A few days later, Nanako runs into Mitsuru again—this time, he’s been fired from his job and appears deeply troubled. Sensing his loneliness, she feels compelled to stay by his side, just for one night. And so, she writes a deceptive letter to her husband.