Jyugo sees Uno, Rock, and Nico as his only family since his mother died at a young age and his father left him.
truth is...
Jyugo's mother was a guard, and his father was an inmate who had a child together. Which explains why Jyugo was put in jail as an infant and never really was allowed to leave. His mother wasn't allowed to keep the child, and Jyugo was taken away from her when he was born.