Ling has been suffering from leukemia since childhood. As an optimistic person, she doesn't take everything to heart, except for her limited life. She always hides her love in her heart and doesn't tell her friends Rex and Otaru about her condition. Since childhood, Otaru and his mother have traveled from mainland China to Hong Kong to make a living by selling fish. With an introverted personality, Otaru is not good at expressing himself. Despite being hot and cold with Ling, they have become good friends who care about each other. Otaru vs. REx had a favorable impression, but Rex did not express it, and Otaru did not notice that another boy, Axi, was silently admiring her.