Gu Dae-ro's robot. A cleaning robot that somehow entered the Robot Fighter tournament. Though weak, its light weight makes it ideal for fast movement. It has arms and legs.

Lazy, but will do anything if his pride is wounded. When he enters the robot fight, he gets distracted thinking, "Everyone is cheering for me..." He was unemployed but bought Kkalkkeumi from the Robot Shop Owner for 422,600 won. He is friends with Man-ho, who used to do robot fighting as a hobby. He belongs to the 5th League 'Passion Team' along with Man-ho.

Used to do robot fighting as a hobby but quit. He belongs to the 5th League 'Passion Team' and has a crush on Gu Dae-ro's older sister. He is the one who taught Gu Dae-ro the basics of robot fighting.

Shortened to 'A'. A white-haired trainer for Man-ho and Gu Dae-ro who has a split personality. Usually kind, but if a training session fails, he coldly orders them to "Get down on the floor" and gets angry.

The coach of the 5th League 'Passion Team'. He is the one who recruited Gu Dae-ro and Man-ho.

The youngest professional fighter. Despite his young age, he has the skills to toy with adult amateur players.

Lim Young-jae's biological father. He is also a former fighter.

Lim Young-jae's robot. It possesses speed that ranks among the best, even when compared to the robots of top-tier fighters.