Aika Ito, is 27 years old. She and Shinya, a high school classmate, got married after 10 years of dating and soon ended up pregnant. Though things were smooth sailing, Shinya was assigned to work abroad, forcing the two to live in separate countries. After giving birth, Aika visits Shinya for the first time, but when she meets him again, she's met with a cold attitude. Aika is perplexed by the sudden change in her husband. It was in that moment that her husband's colleague, 22-year-old Mona, a local woman, comes to visit...