One day, your father suddenly tells you, "I'm getting remarried." Before you even have time to be surprised, you're moving into a new house. Apparently, the parents will be away on a five-year honeymoon. Nervously opening the front door, the person standing there is— The idol you've been supporting and admiring forever. "...Huh?" Against all odds, your parents remarried, and you've become step-siblings with your favorite idol!? In public, a fan and an idol. But in reality, step-siblings. Knowing his side as an idol, every day is a continuous heart-pounding experience! Laughing, fighting, and gradually becoming a family, your lively life living together begins!