I admit that there is not a particular merit. Schoolboy protagonist Tomohiro Kuchiki. He is going to school in a certain morning, it is unexpectedly wrapped in dazzling light and loses consciousness. When waking up, the place that had not been seen. [Here is where...?] To the presence of puzzled Tomohiro, two girls were standing.

Girls, it is reported that Tomohiro was summoned to the fantasy world by practicing magic. And to the speech that continues further, Tomohiro is more and more surprised, it is puzzled. Because the purpose that they say, to oneself thought there was no merit, by birth "A certain value" there seems to be. With the merit -- the one that there is effect of improving magic in Tomohiro's semen.

Girls fighting against a monster attacking the people need a strong magical power, it pleads to Tomohiro for semen for the purpose to improve magic. Moreover in this world where the chastity idea is high, when sex is one time done it absolutely must get married, both want to marry Tomohiro. So, one man marries two women in the fantasy world however, common sense.

In the fantasy world where all is out of common sense, Tomohiro's newly-married life and every day of battles now starts.