32-year-old Zhang Zhen Dong is what most would call a loser. One night, he gets a knock on his door - a 12-year-old claims to be his Mini-me. Zhen Dong takes the 12-year-old in but little does he know that his life will be thrown into complete chaos. He attempts to hide this boy from his neighbour and building supervisor Ye Xin Jing as he finds a way to bring him back to where he came from. 32岁的张震东，是多数人所称的的失败者。一晚，自称12岁的震东出现在家门口 - 震东不信，试图打发这恶作剧...

Zhen Dong reconnects with Shen Jia Yi, his dream girl who now runs an online business. He soon realizes that she is dating his former best friend, Wu Shi Xiong. Young Zhen Dong bonds with Xin Jing and finds out the truth about his older self. Despite the boy's protest, he is forced to enrol in school. Zhen Dong is surprised to learn that Jia Yi wants him on the team for her upcoming campaign. 因为工作，震东和小学初恋沈佳怡重逢。她创办了自己的网络服装企业，身份和地位和震东有着一定的差距...

Zhen Dong realizes he's crossed paths with Xin Jing in their childhood, while his mini me realizes school in 2021 is different from 1999. Shi Xiong helps Xin Jing secure a job at the gym he frequents. Shi Xiong and Jiayi deliver a reunion invite to Zhen Dong and his mini me goes ballistic upon seeing Shi Xiong. Mini Zhen Dong reveals how he time travelled and decides he wants to return to 1999. 震动发现小时候遇过邻居心靖，而小震东发现现在的学校环境与20年前截然不同。世雄得知心靖在健身房求职...

To Zhen Dong's dismay, Jiayi and Shixiong seem to reach a stronger bond in their relationship. Zhen Dong is called to school and forced to play parent to his mini me. The duo finds the importance of a pocket watch in their time travel attempt. Xin Jing notices their suspicious behaviour at a watch shop. While trying to break down the door, Zhen Dong accidentally triggers the security alarm... 世雄准备浪漫的惊喜和佳怡庆祝周年纪念，两人的感情更甜蜜。小震东在学校捣蛋，震东被训导主任叫到学校...

Xin Jing finds out the truth and the trio search for time traveling answers and search for the time travel club. As the two start to share a love-hate relationship, Mini Zhen Dong tries to find love for his older self, to Grandma's delight. Shi Xiong intimidates Zhen Dong as he brings up the complicated past between them. At work, Zhen Dong musters the courage to present his creative pieces. 心靖帮两位震东逃离商场, 得知小震东其实是穿越时空来到这年代。 心靖无意中也加入了他们的计划...

Mini Zhen Dong calls the elder one out for having feelings towards Xin Jing and Jia Yi. He sees Luo Wei in a different light. Jia Yi disagrees with Shi Xiong's work attitude. With the time travel club's help, Xin Jing and Zhen Dong finally have a solid attempt to send his mini self back but they fail in this attempt. Dejected and frustrated, Zhen Dong reveals a painful truth to his mini self. 小震东自认震东对佳怡和心靖俩都动了情，但震东否认。小震东和心静陪着罗伟为女儿庆祝生日，小震动深受感触。。。

Zhen Dong duo gets into a fight as the truth about their parents is revealed. Xin Jing finds herself worrying about them both. At work, Zhen Dong shows his fun side to Jia Yi. Mini Zhen Dong takes his frustration out at Shi Xiong, jeopardizing his career. A gathering takes place at the apartment where Luo Wei recognizes the pocket watch and Xin Jing realizes she is also connected to that watch. 小震东狠狠责怪大震东隐瞒真相。心靖安慰小的，也劝震东别把自己的不幸归咎于他人。。。

A struggle breaks out and Luo Wei takes his pocket watch back from the duo. Zhen Dong and his mini me call it a truce and join hands to get the watch back. With the help of Xin Jing and Grandma, they attempt to help Luo Wei find his family. Xin Jing reveals her connection to the pocket watch. At work, Zhen Dong faces difficulties but takes a leap of faith and gets rewarded by Jia Yi. 当罗伟意识到小震东拿着的是他20年前丢失的怀表时，他急忙抢回怀表。大家得知罗伟和家人失散。大小震东决定抛开对彼此的愤怒...

Luo Wei explains the works and rules of time travel to the two Zhen Dongs. Xin Jing has a family struggle she must overcome. When Zhen Dong is backstabbed at work, Shi Xiong comes to his defence. As Zhen Dong and Shi Xiong's relationship starts to go on the mend, Zhen Dong is confronted by his younger self. Shi Xiong is unsettled when he discovers that Mini Zhen Dong is not who he seems to be. 罗伟解释穿越时空的运作方式 - 必须等到11月11日带着怀表到表店才能回到1999。。。

Months on, the residents have become a tight knit family. At work, Zhen Dong is receiving more recognition. With Luo Wei's help, both Zhen Dongs prepare to time travel. At the highly anticipated Primary School Reunion, Jia Yi makes a shocking decision. With no time left, Zhen Dong confesses to Xin Jing. Shi Xiong digs into Zhen Dongs and is sure but shocked to find out they are one and the same. 几个月后，大家似乎习惯了新生活的状态，大小震东对彼此有一定的影响，和罗伟跟心靖俩感情更深。。。

11/11 - it's the day the duo will time travel. A furious Shi Xiong ransacks Zhen Dong's apartment and shatters the pocket watch. With Luo Wei and Xin Jing's help, they find a way to fix the watch. Shi Xiong spies on their plan. Fearing his fate will change, he turns up at the watch shop to stop them from traveling back in time. In the midst of chaos, Shi Xiong is swallowed by the light with them. 世雄闯入震东家，把整个家打翻，把怀表砸得粉碎。但今天是11月11日，穿越时空的日子...

The duo is back in 1999, and Shi Xiong is unconscious. Zhen Dong and his mini me rushes home to execute their plan, with Zhen Dong keeping out of sight, a reminder from Luo Wei. Shi Xiong jolts up, realizes where he is and attempts to stop the duo at school where it all began. But soon, the 3 realize the events that unfold on 11/11 is not how any of them remembers... 大小震东醒来发现已成功回到1999年，两人看到在一旁仍然昏迷不醒的世雄，但时间紧迫，决定不管他，先赶回家。 震东见到父母和小震动团聚时，想紧紧的拥抱他们...