It's been six months since she became a working adult. Pressured by work daily, she has even lost the energy to find fun. One day, Yui is summoned to another world! She is summoned by Jade, a mage of the Tine Kingdom, which is under invasion by a demon tribe, and he asks her to do something for him. He asks her to "seduce the demon tribe" as the guardian of the Tine Kingdom!