Soundtrack #2 follows the story of Hyun-seo and Su-ho, a couple who dated for six years during their college days but eventually broke up due to the pressures of reality and misunderstandings. Years later, their paths cross again under unexpected circumstances: Hyun-seo is now a piano tutor struggling to make ends meet, while Su-ho has become a successful, wealthy CEO who is suffering from burnout. As they reconnect, the series explores the complexities of their past relationship and the lingering feelings that never truly faded. Through the medium of music, they begin to navigate their current lives and confront the unresolved issues that led to their separation, ultimately questioning whether a second chance at love is possible when life has taken them in such different directions.