As a boy, his father took him up to the surface with him, but at that time, Kamina did not have the courage to stay up there, so he returned to the village alone. Now, he wants to meet his father and live out on the surface - a place where there are no walls or ceilings. Although the other villagers call him crazy and stupid for his foolish dreams, he intends to get up there.
He looks after a young boy named Simon like a younger brother. Although they are not blood-related, Kamina declares them to be soul-brothers, and encourages him to call him aniki ("big bro"). He constantly encourages Simon to be a better person, and believes that his drill will break through to the heavens.