Twenty-nine-year-old Han Seo-jin is a cold, meticulous architect known for her flawless designs and even more flawless emotional walls. She's built a life of routine and solitude in Seoul, where feelings are distractions and love is a luxury she can't afford.
Then comes Jung Ha-joon, a warm-hearted, struggling florist with a mysterious past and a smile that blooms brighter than his flowers. When Seo-jin is forced to move into a quiet rooftop apartment after a personal crisis, she discovers that Ha-joon runs the flower shop downstairs. He seems like everything she isn't: spontaneous, emotional, kind.
Their worlds collide when a lost diary, once belonging to Ha-joon's late fiancée, ends up in Seo-jin's hands by fate or maybe destiny. The more she reads, the more she learns about love, loss… and the secret connection between them that neither of them expected.
As cherry blossoms fall and old wounds begin to heal, Seo-jin and Ha-joon must decide: will they risk their hearts for a second chance at spring?