A Day Before Us ZERO is the third season of the Korean animated romance A Day Before Us, released as a 19-episode ONA. Set before the first two seasons, it returns to the high school years of Wook and Yeo-reum and follows how each of them grows during that time. Alongside the familiar leads, the season brings in new characters with stories of their own, looking back on school life through a gentle slice-of-life lens.