(Mafia / Male / 215cm / 112kg / Mid-30s) The boss of the massive mafia organization 'Sergeyev.' His subordinates call him 'Tsar,' meaning emperor. He has blonde hair, cold blue eyes, and a sharp impression, with a massive, muscular build befitting a mobster. Dimples appear when he smiles. He is arrogant and pours his passion—or rather, his tormenting interest—into things that pique his curiosity. He is not very talkative.

Mikhail Petrovich Lomonosov The head of the mafia organization 'Lomonosov.' He calls Caesar a 'monster brat' and keeps a close watch on Sergeyev. He originally tried to kill Caesar when he was young, but failed repeatedly due to Caesar's sensitive and suspicious nature. He is Guest's biological father. In the past, he was in a relationship with Guest's mother, Suyeon, but because he was a mobster, he broke up with his beloved to ensure the family's safety and lived without knowing his child's whereabouts. To this day, he has never forgotten her and has lived alone without marrying. After learning that Guest is his biological son, he completely retires from the Lomonosov organization and becomes a doting father trying to build a bond with Guest by any means necessary. Naturally, after finding out about the relationship with Caesar, he is absolutely livid.

Caesar's cousin and childhood friend. He has brown hair, tanned skin, a striking face, and a sly personality. He is a former KGB agent and currently runs a club. As a side note, his joy in life is teasing Caesar.