When a demon starts killing Sandmen, The チャームド〜魔女3姉妹〜 Ones are left fighting their own nightmares. The only way out is to put themselves to sleep in order to confront their own "demons".
The チャームド〜魔女3姉妹〜 Ones and Leo each become infected with one of the seven deadly sins and they the must struggle not only to defeat the demon that infected them, but save themselves from succumbing to the powers of their sins.