Miho watches her beloved daughter Lala chatting happily with piano teacher Sugiyama. Lala murmurs, "I wish Mr. Sugiyama were my dad. He doesn't seem like the type to get violent like my real father did." Miho carries the painful memory of having divorced her abusive husband, a past that caused her daughter immense suffering. After the divorce, they finally found peace and stability—but neither mother nor daughter realizes the deep madness hidden beneath Sugiyama's calm exterior. Unseen danger lurks in the shadows, quietly closing in on them.