When a travel magazine advertised online for a reader model for a hot spring location experience project, the target that showed up was Koko-san. A wife who seems to be dissatisfied with her husband, an overly serious systems engineer. Perhaps Kokoro down she had a desire to cheat. The whole thing was a prank location shoot, and by the time the after-party came around, she had been embraced by a man she had never met before...