夏木（乔振宇饰）是一位有着双重性格的资深心理师，性格非常沉闷但是骨子里却又很闷骚，有着典型的直男审美观，今年已经32岁，和前妻离婚过着单身的生活，并且还是过着和年龄不符的退休生活。欧阳欣（唐艺昕饰）是夏木所拥有的另一人格，和夏木本身性格有着很大的差异，她恶毒真实身份一直是个谜团。

Long, the main character, spends his youth wandering with his three best friends from high school. With the emergence of a woman, Dongdong, whom they all fall in love with, their friendship begins to fray. One day, Dongdong suddenly disappears in an ambiguous situation, and the friendship ends. After many years, the friends meet again. However, just as youth cannot return, they can only confirm that their friendship cannot be restored.