Song Xinuan's world is always sunny and full of fireworks. Next to her is Si Chengze, who she grew up with and is always calm and outstanding. One is cold, the other is hot, the other is moving, they are family friends, they are neighbors, they are the most familiar scenery in each other's youth.
From the youthful ignorance on campus to the side-by-side struggle in society, they shared the morning light and sunset on the way to and from school, overcame countless learning difficulties, and felt the beating of their hearts during weekend outings. However, the precocity and forbearance brought about by family changes made Si Chengze bury the emotion that transcended friendship deep in his heart; while Song Xinuan, amidst his academic inferiority and his unique fondness for himself, was unable to distinguish whether it was love or not.
The college entrance examination separated them for a short time, and the college life between the north and the south made the contact less and less, and the topics seemed to be no longer in sync. But the red thread of fate has never been broken. When they meet again in a familiar city and enter the society, facing the challenges of work, family ties, and the ups and downs of emotional entanglements among close friends (such as the fiery best friend Fang Qing and the arrogant brother Song Xichen), the throbbing that has been buried in the depths of the years begins to quietly revive.
This is a story about companionship, growth and finally seeing each other's feelings clearly. They were the footnotes of each other's youth, and will eventually become the destination of each other's lives. From childhood sweethearts to standing side by side, what they need to learn is not only how to become better selves, but also how to bravely walk towards each other.