Yuusuke Satou, a 27-year-old office worker, is a simple man with simple tastes. When he is not in a suit being a diligent salaryman, he can be found lounging on the couch in his sweatsuit with a game controller in hand. He gets along well with Tamaki, his younger sister and housemate, and he feels content. If he were to rate his "adulthood level," he would give himself passing marks.

At least, that was how Yuuske felt before attending a reunion party. He did not think his signature jeans and hoodie would be out of place, but when he arrived, he noticed everyone was dressed so fashionably! When did people start caring about watches and color-coordinated socks?

Realizing that he is utterly lacking sense for fashion, Yuuske returns home full of despair and regret. Taking pity on her big brother, Tamaki—whose hobby and passion is all things fashion—volunteers to teach him how to look his best for any occasion and on any budget so that he is never left out again.