خلاصه داستان : داستان درباره‌ی پسری به نام هیدا کیزونا می باشد که به درخواست خواهرش به آکادمی دفاعی Ataraxia می‌رود، در آنجا با دختری به نام شیدوریگافوچی آینه روبه‌رو می‌شود که صاحب زره جادویی Zerosu بوده. ناگهان، “آینه” لباس‌هایش را جلوی هیدا در‌می‌آورد و به او می‌گوید “نگاه نکن منحرف!” و هیدا پاسخ می‌دهد که “من منحرفم...

Hida Kizuna possesses the HHG (Heart Hybrid Gear) ability, but it is not strong enough to make him particularly important. His older sister calls him to transfer to a strategic defense school, where many of the students (many of which are large-breasted girls) use their HHG abilities to fight invaders from another world while wearing extremely skimpy pilot outfits. Kizuna's fighting ability doesn't measure up, but his sister has another plan—apparently having erotic experiences with Kizuna will allow the girls to replenish their energy or power-up. It looks like his new school life is going to be full of embarrassment.