After six months of working as an office employee, Yui is completely worn down by her daily grind. One day, she suddenly finds herself transported to an unfamiliar world. Before her stands an impossibly handsome mage named Jade, who explains that he summoned her. When Yui begs to be sent back to her original world, Jade makes a promise: if she helps him accomplish his goal, he will return her home. The task, however, is a nearly impossible one—she must seduce the demon tribe that threatens the Tine Kingdom and turn them into the kingdom's protectors.

Yui protests that she has virtually no romantic experience, but Jade refuses to listen. Left with no choice, she reluctantly agrees to try. To her confusion, Jade immediately becomes overly protective of her, intimidating and driving away any demon that approaches. His behavior contradicts the mission he gave her, yet Yui finds herself gradually drawn to him. As their interactions deepen and Jade conducts "practice" sessions to help Yui become more comfortable with men, a new emotional bond begins to form between them. However, Jade harbors a secret that must never be revealed, adding tension to their growing relationship. The story follows Yui navigating an unfamiliar world, her impossible assignment, and the unexpected feelings that develop between her and the handsome mage who summoned her.