Chained Soldier Manga Volume 1 (Mature)

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?!