Date A Live IV episode 11, "Past Sins," reveals Kurumi Tokisaki's tragic origins, showing she was manipulated by Mio Takamiya into becoming a Spirit and unknowingly killing her best friend, Sawa. The episode, covering the end of volume 16 of the light novel, also features a Valentine's Day subplot where Shido works to seal Kurumi's powers. Detailed episode information is available at Fandom .