Yuna, trapped in the world of succubi, is given the challenge of seducing Vulcan, a man who despises succubi, as a test of her skills. Vulcan, bitter due to his past, resists, but his succubus friend uses Yuna’s body to attack him with seductive techniques. To return to her world, Yuna must reach the Succubus Queen in a castle protected by a barrier, all while continuing her daring training as a succubus.