"Let's deepen our friendship at our annual camping trip..." was the invitation handed to me by the chairman, Ozawa, one day. My wife, Kana, looked troubled, so I tried to make up an excuse to decline. However, I was persuaded that she had just moved and didn't want to put her in a bad position in the neighborhood association, so Kana ended up going camping alone. It was an adult gathering, so I thought nothing strange would happen, but that night, I found out that the only other participants besides my wife were three middle-aged men. I tried calling them but there was no response, and my anxiety gradually grew...