On a live music radio show, a letter arrives from the 23 years in the past. Through the letter, the first love and friendships of five friends are revealed.

Hwayi is a boy living in a farm village, who was raised by 5 fathers who were famous criminals. One day, the group is commissioned to kill a man named Lim and his wife. While the rest of the group feel something odd about this particular contact, Suk-tae is adamant to carry out this job with Hwayi in tow. During the job Hwayi discovers a photograph of a child in Lim's house. Eventually, Suk-tae hands his gun to Hwayi and he is forced to pull the trigger. He becomes ill after committing his first kill and realizes that the boy in the photograph looks uncannily familiar. Written by Anonymous

Ji-Sun (Uhm Ji-Won) and her physician ex-husband are fighting over custody of their daughter Da-Eun. While trying to perform her job at a PR company, Ji-Sun juggles time with her daughter and winning her difficult custody battle. Ji-Sun recently hired a Korean-Chinese nanny, Han-Mae (Kong Hyo-Jin), to help watch over Da-Eun. One evening, Ji-Sun comes back home from work, but Han-Mae and Da-Eun are not there. Ji-Sun desperately searches for her daughter. The outcome of her custodial battle and job commitments linger in the background. Meanwhile, Han-Mae's story is slowly revealed. Written by Watch_Movies

1592 – Joseon: In those days, it was common for the rich to hire the poor to do their hard and dangerous mandatory military duties. They were called ‘proxy soldiers’. A veteran proxy soldier TOW and his comrades are deployed to the south, where the Japanese has invaded. The King of Joseon has decided to seek asylum in China, and as he flees, he orders his young son –18-year-old Prince GWANGHAE– to take over the country’s military command. Vulnerable Gwanghae is devastated, but with Tow’s help, he is ready to fight in that harsh reality.

A detective goes undercover in a drug ring and allies with a member of the drug ring in order to take it down.

In 1994, on the first day that Yoo Yeul went on air as the new DJ of the popular radio show ‘Music Album,' a college girl Mi-su meets Hyun-woo who happens to drop by the bakery she works at. Like the music streaming from the radio, their frequencies slowly come in sync; even when they're apart, the show brings them together through ebbs and flows of events arising from both pure coincidence and inevitability, until the bitter reality sets in and drives them apart...

On the run from a dogged internal affairs agent, a corrupt cop reluctantly teams up with a defiant teen to unravel a conspiracy -- before it's too late.