Yuina, a girl in love with her non-biological brother, lives tormented by her lack of self-confidence. One day, a mysterious voice guides her to an unknown world. Without understanding what is happening, she is attacked by a man. In that desperate moment, she is saved by the specter of a succubus that possesses her body. The succubus defeats all enemies by fucking them, regardless of what happens to Yuina's body and mind.

Thus begins the adventures of Yuina, an insecure girl in an unknown world, “connected” to a perverted succubus.

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.