Chained Soldier

As graduation nears, Yuuki Wakura fears an ordinary future—until he’s suddenly pulled into the world of Mato: an alternate dimension filled with monsters called Shuuki. To combat the threat of the Shuuki, the all-female Demon Defense Force, empowered by Mato fruits granting supernatural abilities to women, was formed. Yuuki in his dire situation is saved by Kyouka Uzen, the chief of the Demon Defense Force's seventh unit. Despite Kyouka's impeccable skills in battle, she has long been held back by her ability, Slave. It allows Kyouka to put a living being under her control, but the Shuuki that she had enslaved until now had all proven to be weak. When Yuuki and Kyouka become surrounded by a horde of Shuuki, Kyouka resorts to using her ability on Yuuki. To her surprise, Yuuki's slave form is much more powerful than she could have imagined. Believing the young man to be the key to unlocking her true potential, Kyouka invites Yuuki to join the Demon Defense Force.