Hybrid x Heart Magias Academy Ataraxia

Hida Kizuna has the HHG ability, but it's not particularly strong. His older sister sends him to the strategic defense school, Ataraxia, where students use their HHG abilities to fight invaders from another world while wearing pilot outfits. The school's student body includes many girls with large busts, and they're required to use their abilities to fight. Kizuna's sister believes that intimate relationships with Kizuna may help the girls replenish their energy.