A married man named Sei, whose wife Mariko is older and his former colleague, receives a threatening message from their boss Hiroshi about how such beautiful and quiet women like her are likely to cheat. Feeling anxious, Sei gives Mariko a smartphone as a gift, hoping she would use it more often. One day while monitoring her location through the app, he discovers that she's heading towards a love hotel district. Her movements remain untraceable for three hours inside the hotel before resuming... Delivery methods may vary depending on the recording content.