Kim Do Gi is the primary taxi driver for Rainbow Transportation. He also serves as the undercover specialist and special forces trained fighter on missions. His own personal experience having his mother murdered by a serial killer makes him a determined advocate for those in need, who have exhausted all legal means to find justice. But this season will hit close to home for him when a close friend from his military days is killed and accused of treason. And when Do Gi disappears back into the military to find out what really happened to her, the team will have to pull out all the stops to find him and join in his personal mission.

In the beginning of this series, Kim Do Gi was a person with a personal vendetta who was trying to relieve his own grief. But as the series has gone on, he has become the loyal protector of his team and their moral compass. His ability to go undercover in any capacity has also taught him how to mask his own feelings. But over time, he has learned to be vulnerable with those he cares about. Lee Je Hoon is such an outstanding actor. Watching him in all his undercover characters is one of the highlights of this series.

An Go Eun is the dispatcher for Rainbow Transportation. She is also the team hacker, easily breaking codes for security systems and computer networks. As the only female on the team. she is also required to go undercover from time to time. She joined the group because her sister was driven to kill herself after being targeted by bullies. For her, the desire to help those who have been hurt by a lacking and corrupt justice system is the thing that motivates her to do what they do. This season, she doesn’t have her own personal storyline, but she is deeply affected by the suffering of her teammates, especially Do Gi, who she shares a special bond with.

An Go Eun is intelligent and empathetic. She acts as the emotional support for the team and for their clients. After losing her older sister, Go Eun was angry and alone, but over time the Rainbow team has become her new family. Pyo Ye Jin is a good actress and I love her in this strong but sensitive role. She offers a great balance between hard-edged justice against criminals and quiet love and support for those around her.

Jang Sang Cheol is the CEO of Rainbow Transportation. He runs the company alongside his non-profit organization Bluebird Foundation. His main responsibility in the team is supplying the financial backing they need for their missions. Sang Cheol started Rainbow Transportation after his parents were killed by the same serial killer who killed Do Gi’s mother.

Choi Gyeong Gu is one of the mechanics for Rainbow Transportation. Unlike the other members, Gyeong Gu experienced injustice first-hand when he was unjustly accused of a crime and sent to prison. But when Seong Cheol helped him to prove his innocence, Gyeong Gu became fiercely loyal to him and joined the team to help others find justice.

Park Jin Eon is the other team mechanic. Unlike all the other members, Jin Eon has no direct personal experience with injustice. But he believes in the cause of Rainbow Transportation and the team members he works with. His quirky, out-of -the-box inventions have saved them on multiple occassions, and the team is often in turn amused and grateful to him.