Rufen is stuck doing the chores for the party of adventurers he belongs to, especially Sho, the hero who was summoned to this world from Earth where he used to be a high school student.
Rufen wants to fight, too, but he just isn't as strong as everybody else.
Saddened by the thought that they may go their different ways now that they have finally slayed the magic dragon, he and his crew return to the royal city, but they're met with a surprise... and Rufen ends up becoming a woman!

Now that his gender has changed, will his relationship with Sho change as well...?