In his previous life, Gu Yanshen was a cold and distant young man. He witnessed Lin Wanwan withering away due to campus bullying and family breakdown, but he chose to remain silent due to his own emotional barriers and family pressure. He remembered the scars on her wrists, her shaking shoulders when she lowered her head, and even received her desperate text message three days before her suicide, but only replied "Have a good rest." On April 15, 2018, she ended her life with a razor blade in the bathroom. When he arrived, only a pool of blood and her faded sunflower hairband were left. For the next eight years, he lived with endless regret and became an architect, with her shadow hidden in every work. At the age of thirty-five, he suffered a heart attack from a painting of sunflowers on the streets of Paris. Before his death, he made a wish: "If I had it to do over again, I would definitely save you."
When he opened his eyes, he returned to September 1, 2015, before the start of his first year of high school. This time, he waited in advance with all his memories. He gives her warmth anonymously, learns expression awkwardly, and fights the whole world for her. He gave her a whale bone pendant and said, "When a whale falls, everything comes alive" and told her that existence itself is meaning. He accompanied her through dark moments such as the recurrence of depression, the second abandonment by her mother, and the plagiarism of her works. When April 15th came again and she rushed to the same rooftop because of the threatening letter, he had already locked the door and hugged her tightly from behind: "Wanwan, I am here this time."
