Illustrator Lin Wan has had a secret crush on her editor-in-chief Jiang Xu for ten years. However, she accidentally flips through his secret crush diary, where the girl he likes loves sunflowers, has a scar on her left hand, and is afraid of thunderstorms—none of which match her at all. Believing he loves someone else, she traces along half an old ticket stub, only to uncover a forgotten memory in her own mind: ten years ago on a rainy night, she saved his breakdown-stricken sister, sat with him the entire night, left an umbrella and flowers, and subsequently lost her memory. He has been yearning for ten years, knowing all along even when she peeked at his diary, intentionally leaving it unexposed. The white moonlight turns out to be herself, and their mutual unrequited love finally comes true.