Music producer and composer Ha Rib made a contract with the devil to trade his soul for fame. This devilish transaction brought him all the fame he could ask for, producing many hit songs. As the contract expiration draws near, he bargains with the devil for an extension. For that, he must find another person to sell the soul. Ha Rib finds a perfect candidate, but contemplates because she would have to suffer for 10 years for his selfish fame.

After confessing her love in elementary school to her crush, Maewnam is literally crushed when he rejects her in front of all his friends. He calls her ugly and it's at that moment that she decides to wear a box on her head. Maewnam is really damaged by those events and she hides behind the box, truly believing that she's ugly. Forced to return to school, Maewnam meets Minton and Zero. Minton is sweet, friendly, and new to the school while Zero is a notorious troublemaker who uses his fists to solve his problems. The question is: who's the boy that called her ugly all of those years ago? Is it Minton? Is it Zero? Is it another person?

Could anyone be more excited to reach her 25th birthday? Pi Ya Nuo had an inauspicious start to her life. Doomed to live her life as a boy, Ya Nuo is shy and always tries to keep her distance to people to hide her true identity, and the mysterious aloofness makes her irresistible to the girls around her. With her 26th birthday fast approaching, will Ya Nuo find her much-anticipated return to being a female will be as easy as she had hoped?