Cheng Xuan loves to laugh. When he smiles, his eyes will squint, his mouth will open, and his big white teeth will stand out clearly in the light. Yan Zi doesn't like to laugh, but Yan Zi likes to look at Cheng Xuan laughing with a pair of clear and cold eyes. Ever since she was sixteen years old, Yan Yan has loved watching Cheng Xuan laugh. Little Taiyang's smile is her salvation.