Sometimes one splash is all it takes to make waves. Swimming prodigy Woo Seungwon, whose very being is vast and endless like the ocean, runs into former a-list singer Doh Si-on. Si-on, now a businessman trying to stay afloat, is doing his best to move forward with his life; but the weight of the world only drags him down, as if he is struggling to crawl through a swamp. Taking an interest in Seungwon, Si-on offers him the opportunity to make some extra money as his housekeeper…and perhaps do a little extra work on the side…