In "Taxi Driver 3," Lee Je-hoon heads to Japan to dismantle an international crime organization. The first episode of the SBS Friday-Saturday drama "Taxi Driver 3," which aired on November 21, depicted Kim Do-gi (played by Lee Je-hoon), Jang Sung-chul (Kim Eui-sung), Ahn Go-eun (Pyo Ye-jin), Chief Choi (Jang Hyuk-jin), and Assistant Park (Bae Yoo-ram) uniting for the victims. They joined forces to find high school student Yoon Yi-seo (Cha Si-yeon), who was caught in the trap of a global illegal private loan and human trafficking crime and was in danger.

Kim Do-gi re-summoned "Teacher Hwang In-sung" to find out what happened to Yoon Yi-seo and headed to the high school she attended. There, he met Yi-seo's friend Ye-ji. Ye-ji tearfully recalled the past, saying, "This happened to Yi-seo because of me." Ye-ji asked Yi-seo to play a game for her briefly and attracted Yi-seo's attention by exchanging the points earned in the game for cash. Coming from a poor family background, Yi-seo was tempted by the unexpected money and got addicted to the game. At first, she won points, but from a certain day, she started losing points more often.

Yi-seo played the game using points received through the "Advance Points Giveaway" event, which was the start of the problem. Kim Do-gi lamented Yi-seo's situation, saying, "A 300,000 won loan grew to 1.5 million won in less than half a month." Yi-seo could not handle the debt, and gangsters suggested an "easy way to repay the money," proposing she work in Japan for a month. Thus, Yi-seo headed to Japan alone.

Kim Do-gi expressed anger, saying, "Student Yi-seo was dragged into a quagmire." The Rainbow Transportation team targeted a vicious global illegal private loan organization that lures minors with little social experience into the swamp of mobile gambling and uses them as tools for human trafficking. They headed to Japan and began a full-scale search for Yi-seo. To do this, Kim Do-gi had to infiltrate the crime organization.

Kim Do-gi first subdued the henchmen of the crime organization. The members showed Kim Do-gi's image captured on CCTV to the boss (Kasamatsu Sho), and the CCTV footage showed Kim Do-gi provoking the boss, raising tension.

In the second episode, which aired on November 22, the Rainbow five were shown united for the victims. They received a call from Yi-seo and learned about her situation. They headed to Japan to punish the crime organization that lures minors into mobile gambling and uses them as tools for human trafficking. In Japan, they discovered that everything from mobile games to loans and job placement was part of a crime cartel, and they identified an organization called "Neko Money" behind it.

Kim Do-gi provoked Matsuda (Kasamatsu Sho), the boss of "Neko Money," and had a private meeting with him. Kim Do-gi fought Matsuda one-on-one, and Matsuda, who was gathering capable members, liked Kim Do-gi's fighting skills and proposed that he join him. To gain Matsuda's trust, Kim Do-gi spoke bluntly to him, something no one else dared to do, and earned his trust by saving Matsuda in a crisis.

Matsuda shared his story with Kim Do-gi, saying, "I've never trusted anyone before. Whenever I trusted someone, I was the one betrayed first. So my choice was to betray first." Then Matsuda proposed to Kim Do-gi, "Not as a subordinate, but as family. Let's become sworn brothers." Kim Do-gi accepted, and Matsuda held a grand welcome ceremony for him.

However, people from Matsuda's past Yakuza life intruded on the welcome ceremony and made a mess. Taking advantage of the chaos, Kim Do-gi took Matsuda outside. Matsuda brought Kim Do-gi to his hideout, where, as Kim Do-gi expected, all important documents were gathered. Matsuda later realized that the necklace-type USB he always wore around his neck was missing, and it was in Kim Do-gi's hand.

Matsuda angrily asked, "I was going to give you the whole world. Why are you doing this?" Kim Do-gi replied, "The vacation is ending. Yi-seo has to go back to school," and fought Matsuda. At that moment, Matsuda aimed a gun at Kim Do-gi, but the Japanese police, who had infiltrated the scene, shot Matsuda first, saving Kim Do-gi from danger.

The vicious crime organization was thus dismantled, and Yi-seo was able to return safely to Korea. Having wrapped everything up neatly, Kim Do-gi informed the Rainbow Transportation team that taxi operations were over.