Akane "Hatano Yui" and Yukiko "Kawakami Yuu" prepare a hot spring trip for their best friend, Misaki, who is about to get married. The three of them arrive at the secret hot spring [Kagonawaya] surrounded by mountains and rivers. The next morning, when they woke up, there was no Misaki in front of them, and her body was tied up with hemp rope. The three people who thought they were happy each other have their own circumstances, and when the terrifying secret of [Kagonawaya] comes to light...
