Happy!

After her parents' death, Umino Miyuki was forced to give up a promising future in tennis to take care of her three younger siblings. Her elder brother, in a plan to become rich, disappears, leaving a 250 million debt on his sister's shoulders. Two debt collectors seek her out for payment and inform her that she will be forced to work as a bath hostess at a bath house if she cannot come up with the money. Miyuki makes up her mind to become a professional tennis player in order to win the prize money. She seeks for help from the son of a famous tennis family, Ootori Keiichiro, who was also her senior in middle school and fellow tennis player. Will Miyuki be able to become a pro and pay off the debt?