Intro. Anton Lee is a South Korean national swimming icon whose life has been "frozen" since his mother’s passing five years ago. For him, the pool is the only place where his tears are invisible. However, his world is upended when his father remarries. Feeling betrayed and convinced his father has too quickly erased his mother’s memory, Anton retreats into a shell of resentment.
Everything changes with the arrival of Carmen, his 17-year-old stepsister. Unlike the rigid and wounded Anton, Carmen is a high school student radiating warmth and gentleness. Her presence begins to bring color back to a home that had felt like a tomb. As Anton struggles between loyalty to his late mother and the unexpected comfort of this new family, he realizes Carmen isn’t an intruder, but the missing spark he’s been yearning for. Now, Anton must decide: continue drowning in the past or dive into a new future with the family he never asked for, but desperately needs.