The 6th and 7th Squads team up to rescue the abducted Yuuki, kidnapped by a humanoid Shuuki...who turns out to be his long-lost sister Aoba. Upon learning about their situation, Yuuki tries to convince his sister to let go of her hostility toward the Demon Defense Force, but their conflicting ideals lead to a fierce battle between the two siblings!

As Himari is cornered by her elder sister Yachiho’s special technique, will her training with Yuuki pay off!? And next up is a high-power match between Shushu and Sahara, but in the heat of battle a new enemy catches both squads by surprise!

Yuuki’s barely had time to get used to his new role as slave-cum-caretaker when the 7th squad sorties to eliminate a nest of contemptibles. Awaiting them there is Unihorn, the monster responsible for destroying Kyouka’s hometown, as well as a girl with a familiar face...!

Otherworldly spaces known as "demon cities" appeared in various parts of Japan, and those who partook in the “peaches� growing there gained unique abilities-but only if they’re girls. One day, a down-in-the-dumps high school boy named Yuuki Wagura suddenly gets lost at the entrance of a demon city. There, he meets Kyoka Uzen, the beautiful leader of the seven programs of “Magical Defense Corps,� whoo orders him to become her slave?!