They were childhood sweethearts and he was always protective of her like a big brother. After many years, the two separated and lived in different places. When they meet with their significant other, when they are betrayed at the same time, when they are forced to be together by their parents, they are still like a big brother and a little sister, but the seeds of love in their hearts have already sprouted, but this love is confused with brother-sister love. Can they transcend the love between brother and sister? Open the door to love and move towards sweet love??