I guess we're destined to never be apart

Seungwan, who is one year older, and Sooyoung, who is younger. Sooyoung had a lot of regrets while dating Seungwan, and when Seungwan transferred schools due to family issues, they grew further apart and the regrets piled up even more. So they had a fight and Sooyoung broke up. A year later, Sooyoung went to work for the first time after graduating and met Seungwan, who was an intern at that workplace.