In 1990, Myung Jae enrolled in a major he wasn't interested after studying three years for college and spending meaningless days in class. But he fell in love with Seo Young at first sight and joined the singing club to be with her. But Myung Jae feels that Jung Woo, a golden boy majoring in dentistry, is a competition. At a club gathering, Myung Jae and Seo Young rode the duck boat and he extends a hand but she pushes him away. Myung Jae is devastated and that's when he's called to join the army. Meanwhile, Jang Mi is in love with Jung Woo. The two hold hands in the dark. He suggests attending the song festival with him. But Jang Mi's mother cuts off Jang Mi's hair so she couldn't attend the song festival. And her one-way love is over. In 1996, Myung Jae and Jang Mi who each failed at their first love, meet at a bank by coincidence. Is that reunion a lottery or lightning? - KBS World
The plot is centered around the 10 year relationship between Yoon Seok Hyun and Joo Yeol Mae, who have been repeatedly breaking up and getting back together the entire duration of their relationship. Tired and looking for love elsewhere, Joo Yeol Mae turns her attention to Shin Ji Hoon and leaves Yoon Seok Hyun to look on with envy.