It is spring of the year 1999. At a high school in Gyeongju (an ancient capital located in the southern region of Korea), Dan-hee (Kim Hee-Seon) is famous among the guys as an eccentric girl who plays baseball, and Ha-jin (Lee Dong-Gun) is renowned as the handsome class president who has overcome his past as an orphan.

On the other hand, Yoo-gang (Yun Se-Ah) is a loner who is ostracized from her peers because of her melancholy character, but her eyes are always on Ha-jin. Years later, in the spring of 2006, Ha-jin comes to Jae-myung’s (Lee Jin-Wook) rescue when he is in need of help, and the two become best friends. Jae-myung is the son of the President of Mirae Chemicals, and his recommendation lands Ha-jin a job.

The President orders Jae-myung to coach the company’s softball team, in hope that it will discipline him. Dan-hee has respected Jae-myung as a baseball player for a long time and has high hopes for his influence as a coach. At first, Jae-myung scoffs at the softball team, having been a baseball player all his life, but begins to find motivation while working with the team through Dan-hee’s passion and diligence. He sets new goals to transform his team into a champion team and to make Dan-hee into the best pitcher in the game. During this process, he falls in love with her. Dan-hee is also attracted to Jae-myung, but finds it difficult to open up to him after the scar left in her heart by her first love. Jae-myung becomes curious about this man who has hurt Dan-hee so deeply…

Ban Ha Jin (Lee Dong Gun), an orphan and high school drop out, is calculating and ambitious. Even though he dropped out of high school and lives with Choi Yoo Kang (Yoon Se Ah) due to extenuating circumstances, he used to be the high school president and hoped to go to college. Through coincidence, he meets Yoon Jae Myung (Lee Jin Wook), the popular former baseball player from high school, at a bar in Switzerland. Ha Jin manipulates a series of events to become Jae Myung's best friend. Also coincidentally, he meets Oh Dan Hui (Kim Hee Sun), the girl he loved and hurt in high school. Oh Dan Hui used to play baseball on the boy's team but now plays softball in college. Her baseball hero is Yoon Jae Myung. All three meet again in Switzerland and again back in Korea. Ha Jin starts working in Jae Myung's father's company and does everything to make the rich chairman like him. Jae Myung starts working as the softball coach of his father's company's team but then gets transferred. He falls in love with Dan Hui who's headstrong and optimistic personality attracts him. He asks Ha Jin for advice, but Ha Jin cannot bear to watch Jae Myung take his true love.