Chizo Kamiya, a seemingly ordinary office worker, has a secret. It is that she can see "a certain number" above a person's head. That number is the number of days since the person last had sexual intercourse, or in other words, "purity fighting power!" Because of this ability, Senzou, who once broke up with her boyfriend after learning that he was cheating on her, has been interested in Miyoshi Kiriri, a high-spec boy in her class, but has been unable to take the first step forward. There was one more thing that was bothering Senzou. That is, the number above Miyoshi's head is over 10,000, which means that he is a virgin. "Why is it that he is handsome, good at his job, and has a good personality?　Why has he never had a girlfriend?"　I wondered, and then, at a drinking party, we started talking about his past relationships. 一見ごく普通の会社員、神谷千桜には秘密がある。それは人の頭上に数字が視えること。 その数字とは最後にエッチをしてからの日数、いわば『清純戦闘力』！　 この能力のせいで彼氏の浮気を知り破局したことのある千桜は恋愛に臆病になり、同期の三好桐里が気になっていたものの彼の頭上の数字は1万超え、すなわち童貞で――。 ハイスぺ同期の秘密が視えちゃう、オトナピュアな焦れ焦れオフィスラブ！