After being brutally dumped by her first love, Hyejin becomes a shut‑in. Now 26, she’s decided it’s finally time to escape a life that’s “lagging behind everyone else” and catch up. Dreaming of a normal, everyday life, she starts a part‑time job at a gym. But it turns out there’s a “helper” backing her very first step into this new challenge. Four men begin to gather around the confused Hyejin. Soon, she finds herself in a full set of romantic entanglements with these four men—each relationship as tough and demanding as a workout routine itself.