Manjirou Sano is a founding member and the leader of Tokyo Manji Gang. Mikey is usually a carefree teenager who loves to joke and play pranks around those he considers his close friends. He cares for them greatly and is determined to protect their honor. He rarely shows any sign of weakness, as he believes himself to be the foundation and support for Toman, and if the pillar himself were to display weakness, Toman would also be weakened. As Toman's leader, his aura changes dramatically, becoming imposing and commanding. While its members respect Mikey, they also hold a degree of fear toward him and his immense prowess. He is also concerned for Toman on an individual level, as shown when he decides to rally the entire gang to seek revenge for one of its member's friend.

At the beginning of the story, Yuuichi appears to be a diligent and happy student, who works hard to be able to join his friends on the school field trip. He values his friends heavily throughout the story. He shows kindness and a willingness to self-sacrifice for the sake of his friends, even going so far as to brand himself the traitor in order to prevent further discord. As the story progresses and the games become more and more serious, however, Yuuichi begins to show a much more sinister side. This dark nature is likely the result of his troubled upbringing by an adopted mother who had to sell her body and a con man/swindler who served as a father figure and teacher. He shows little remorse for any of his more devious actions and appears sadistic at points when he takes pleasure in the misfortunes of his enemies.