Eiji Yariba, aged 29, coaches the sales team at Arcadia car insurance's Hachijou branch call center in Tokyo. Despite feeling like a corporate slave, his juniors idolize him as the center's ace. While casually spending his weekend off at a manga cafe, Yariba bonds with a 15-year-old high school student named Karen Minamisato over their shared love for books, particularly writing. However, when Minamisato develops romantic feelings for Yariba, he must rebuff her advances.
To his surprise, Yariba is summoned by the CEO of Arcadia's Japanese subsidiary, Takayashi Takamishi, and ordered to "court" Minamisato. As her grandfather, Takamishi is invested in his granddaughter's happiness and believes Yariba is essential to it. Despite Minamisato's disgust with her grandfather's plan, Takamishi demands that Yariba befriend and mentor her in writing. Yariba must now juggle his sales department responsibilities, personal relationships, and new duty as Minamisato's writing coach while maintaining his strictly platonic relationship with her.
