It's sweet and sour

Ha-jun, a 19-year-old Taekwondo athlete, returns to Daldongne with a smudged photo and a gold medal to find his mother. There he meets Seoyul, a 9-year-old who believes he’s playing hide-and-seek with his missing mom and eats peaches despite his allergy. Seeking clues, Ha-jun follows him, and a fragile bond forms. After learning the address leads nowhere, Ha-jun breaks down, and Seoyul later collapses from his allergy. Ha-jun takes him to the hospital, and with the help of a local grandfather, the two regain trust and warmth. Eventually, Ha-jun finds the real blue gate and leaves his gold medal there, letting go of years of longing. Hand in hand, he and Seoyul walk forward as each other’s new support.