An accidental "snowball attack" in the snow brought Jiang Yan, a fifth-grade boy with mysophobia, and Chi Niansheng, a first-grade girl who is as clingy as a little sun, to meet. From then on, the two people, who are four years apart, have become companions on each other's growth path—— He helps her rub paint, solve problems, and make review plans. She accompanies him to put together puzzles, guard the examination room, and solve scientific research bottlenecks. From kite strings in elementary school, waiting across schools in junior high school, to cherry blossom appointments in high school, laboratory visits in college, and daily fireworks after marriage, in more than ten years, they have grown from the bond of "brother and sister" to a long-lasting love. They have proved with countless warm moments: the best relationship is to grow up together and live every ordinary day into sweet memories.
