Yoshinori returns after six years to his family house, where his mother Etsuko lives alone. His decision to return is sparked by the seventh anniversary of his younger brother's death. He brings along his fiancée Kanae, who is pregnant. Etsuko warmly welcomes them both, but Yoshinori can't help but think that something is strange. That night, Kanae is struck by "a sound that must not be heard", and then the hell really begins.