Hida Kizuna has the HHG (Heart Hybrid Gear) ability, although it isn't powerful enough to make him very useful. His elder sister requests that he move to a strategic defense school, where many of the pupils (many of them are large-breasted ladies) utilize their HHG powers to combat invaders from another world while dressed in exceedingly skimpy pilot suits. Kizuna's combat ability isn't up to standard, but his sister has a different plan: having romantic adventures with Kizuna would reportedly allow the females to refill their energy or power-up. It appears that his new school life will be full of shame.