One day, Ayaha Yamanouchi, who spends her busy days as a general manager of a food company, notices that her underwear is missing from her laundry. She wonders, “Could it be an underwear thief?" but she spends her days in agony without any decisive incident. The next day, she is visited by the police, who say they are investigating a street crime targeting women. Ayaha, who was concerned about her laundry, decides to ask about her missing underwear. Then a handsome police officer appears -Cry Baby Kai-kun..! To her surprise, it was her childhood friend Kaito Shirasaki!