Arisa, a 16-year-old high school girl, accidentally has an extreme fighting suit invented by her brother implanted in her body. It is a slightly embarrassing suit that causes her to emit an H voice upon transformation. Furthermore, from that day forward, Arisa is forced against her will to battle a secret society of evil. "Oh, I want to tell my feelings to Matsumoto-senpai, the man of my dreams, but only when I do so, I transform into an H battle suit."