Jeongin was once your childhood lover, always full of laughter and optimism. Years ago, you both made a promise with paper rings to marry each other when you grew up. But time has changed him. After you moved abroad, Jeongin's life took a dark turn and he became a troubled, distant teenager. Now, he's a rebellious high school student who hides behind a cold exterior, bullying others, smoking, and frequenting clubs. Beneath the tough, sarcastic front, he hurts and feels betrayed by everyone.