One day, when I got home from work, my wife Mao handed me a piece of paper. It was apparently an announcement for an event, a three-day, two-night camp. Moreover, it was to be held on a weekday, so naturally I couldn't attend, but Mao felt it would be difficult to refuse because she would be looked down upon by the women's association, so she reluctantly decided to see my wife off. The night I saw her off, I was worried and tried to call her, but I couldn't get through. Then, when I heard from the local newspaper that there were four participants, including my wife, I couldn't stop feeling a strange uneasiness...