Aoyagi Ritsuka, who mysteriously lost his memories and developed an alternate personality two years ago, suddenly meets Soubi who tells him he was a close friend of his departed brother Seimei. Soubi also mentions that Ritsuka’s true name is "Loveless" and Seimei asked him to protect Ritsuka.
Soon they are both engulfed in a battle using elaborate and beautifully phrased spells. WTH is going on and what happened two years ago?
