Because of their part-demon heritage, Towa, Setsuna, and Moroha have all temporarily turned human-on the same night that yet another assassin aims to take the girls out! In light of that, Towa wrestles with her identity as a half-demon and wonders what her life could have been if she were a normal human girl. Then, she learns the truth behind the attack that caused their parents' disappearance 14 years ago!
