Masato kyobashi suffering from a illness which does not allow him to do any strenous activity becomes the manager of the school's swimming club.
It is a manga about his everyday life in the swimming club surrounded by beautiful girls.

In a world where witches are shunned and have been forced onto the brink of annihilation, a samurai with no memories is transported to the hideout of some of these witches. Having the name: "Dragon King" and a keen strategic mind, its up to him to help defend the witches from those that would seek them harm.