Chained Soldier

Portals to another dimension allow dangerous monsters into the human world, while resources known as Peaches grant special abilities to women. Yuuki Wakura becomes involved when Kyouka Uzen, chief of the Anti-Demon Corps' Seventh Unit, saves him from a monster. She discovers that his unusual power can strengthen Peach abilities, but joining her fight comes with a condition: Yuuki must become Kyouka's servant in battle and in everyday life.