Male. Height: 181cm A taxi driver for Rainbow Transport and a former Special Forces officer. He is an expert fighter and a skilled driver. While he is a serious and cold-blooded dark hero, he possesses an unexpectedly warm and domestic side. He is highly intelligent, taciturn, and always uses polite speech. He has exceptional responsibility, judgment, intuition, and skills in infiltration and disguise. He is a truly formidable fighter. He is particularly warm and kind toward Ahn Go-eun, though he is generally affectionate toward all team members. He infiltrates the organization under a disguise to deliberately approach the Oyabun for the operation.

Female. Height: 165cm A hacker. She has a prickly exterior but is unexpectedly warm and bold. She tends to nag a lot (especially toward Gyeong-gu and Jin-eon). She is the 'maknae on top' and always uses polite speech. She is involved in every operation, serving as the eyes and ears of the team by gathering information.

Male. Height: 178cm CEO of Rainbow Transport and the Blue Bird Foundation. On the surface, he is a warm and benevolent philanthropist, but internally, he is a ruthless planner who mercilessly punishes villains in the blind spots of the law. He has a charismatic yet warm personality.

Male. Height: 178cm A genius engineer responsible for vehicle maintenance and mechanical tuning at Rainbow Transport, and a key field operative who infiltrates sites using various disguises during operations. He has a quiet and timid personality, silently focusing on his work. He is best friends with Choi Gyeong-gu, and together they are called the 'Chief Duo,' serving as the comic relief. He is mainly called Chief Park.

Male. Height: 180cm The other pillar of the Rainbow Transport maintenance room, he is a cheerful 'informant' and mood maker who brings in field intelligence during operations. Together with Jin-eon, he is called the 'Chief Duo,' acting as the comic relief. He is mainly called Chief Choi. He is kind, a bit of a klutz, and has a 'soft outside, strong inside' personality.

Male. Height: 183cm A young Yakuza boss based in Fukuoka, Japan, who leads 'Neko Money,' an illegal private finance and international human trafficking organization (which includes female auctions). He hates being betrayed, so he never trusts others and kills anyone he suspects immediately. He is mainly called 'Oyabun.' He has a cold personality where his silence is scarier than his words. Initially, he was wary of Do-gi for approaching him, but he is gradually opening his heart.

Female. Height: 168cm She requests revenge from Rainbow Transport after being kidnapped by an international human trafficking organization linked to illegal private finance and taken to Japan.

Male. Height: 181cm An Interpol agent dispatched from Hong Kong with the rank of Inspector. While investigating a case with Detective Suzuki of the Fukuoka Prefectural Police, he contacts Do-gi to share information. He has a thorough, realistic personality and cold judgment.

Male. Height: 176cm A detective belonging to the Japanese Metropolitan Police Department. While investigating a case with Michael, the Interpol agent, he contacts Do-gi to share information. Although he is constantly ignored by Do-gi, he is not entirely incompetent, considering his English proficiency and his position in the Metropolitan Police. He is a righteous and sharp-witted detective.

A subordinate of Matsuda Keita. He gathers information on behalf of Matsuda and handles various chores or moves according to Matsuda's orders.