何东（李晨 饰）、何西（任重 饰）、何南（贺刚 饰）和何北（杜淳 饰）是四个自幼生活在老北京城的堂兄弟。生活各不相同的四兄弟，在成年之后各自经历着人生最重要的转折期。老大何东慢慢厌倦了单调的公务员生活，甚至悔掉婚约，只为重寻热血沸腾的青春；何西作为刚刚步入社会的青年医生，爱情是他生活的主旋律，他为了真爱奋不顾身；在海外创业的何南踌躇满志回国，准备大干一场的他面对着诸多挑战；老四何北最令人担心，成天打架胡混，自甘沉沦，但这个脾气暴躁的青年开始打算走上正途。 （英语）He Dong (acted by Li Chen), He Xi (acted by Ren Zhong), He Nan (acted by He Gang) and He Bei (acted by Du Chun) are cousins who were born and raised in Beijing. They lead different lives, and are going through one of life's most important transitions in adulthood. He Dong, the eldest among the four, is getting tired of his monotonous life of a civil servant. He even breaks the promise of marriage in order to find the blood boiling youth again. He Xi, as a young doctor who has just started his career, makes love the center of his life. He is desperate for true love. He Nan, having started a business overseas, returns to China ambitiously, only to find a series of challenges. He Bei, the youngest among the four, is a jobless trouble maker. But the grumpy young man now wants his life back on track again.