Happy!

Sitting in their cramped apartment, Miyuki Umino's older brother talks excitedly about the new business he's starting, promising to hit it big and bring her and their young siblings out of poverty. Months later, Miyuki is approached by creditors working for the yakuza, who inform her of her brother's disappearance and the two hundred fifty million yen loan he defaulted on. With her brother on the run, Miyuki is now responsible for his debt. The creditors give Miyuki an out: to pay off the loan with her body by working in a soapland.

Wracking her brain for a solution without having to resort to prostitution, Miyuki happens upon an article about the current women's tennis champion, who earned two hundred fifty million yen within the previous year. A once-promising tennis player herself, Miyuki withdraws from school in order to become a pro tennis player in hopes of paying off her debt. However, the establishment that pushed her out of the world of tennis has not forgotten nor forgiven her. Can Miyuki succeed within a world of competition actively conspiring for her failure?