Freshman Jiang Youxi unexpectedly meets Jiang Xu, a young man from the future who claims to be the future son of her and He Zhuo. He Zhuo suffers from sleep problems, but finds exceptional peace when spending time with Jiang Youxi. Gradually drawn to Jiang Youxi's bright and warm personality like a little sun, He Zhuo takes the initiative to get closer to her. Through playful bantering and constant tests of affection, the two steadily walk towards each other.