Luka with a mysterious past; Luka, who figths; Luka with his bad and good memories, which Yuki doesn't recognize anymore. How did it happen that the most loved by the Demon King and already marked with the sinners' sign, decided to betray his own allies for the sake of his enemies' source of life, a human female he would have had to kill? Luka's past and Yuki's first life with him.