Once Upon a Time in the Northeast tells a story of a few young Northeast youth with totally different personalities, who fell into trap of a few Hong Kong villains. They outwitted Hong Kong villains using different plans. This comedy story is extremely funny and reflected how popular Northeast China Culture is.

The story centers on the Chinese Special Police Unit, from their hard training to their first mission.

A young girl named Yishu believes she has no luck at all and she blames her name for it. One day she starts receiving phone calls from people thinking that she is the popular singer Tianyou. It turns out that someone has leaked 600 phone numbers of famous people to the internet and Yishu's phone number got mixed up in the bunch. She finds it annoying at first but soon she receives a text message from Xiaowen, who is the singer in an amateur rock band. He wishes to write a song for Tianyou and wants Yishu -who he thinks is Tianyou's assistant- to deliver the song to Tianyou. Tianyou is a popular singer, but hasn't had a hit number lately. Because of this she gets pressured by her cruel agent into recording an album that she doesn't want to record, because it doesn't contain any good songs. This decision gets her into a lot of trouble...