Julius Rapha Holfort is the crown prince of the Holfort Kingdom. His middle name "Rapha" denotes his royal lineage per aristocratic naming conventions. Characterized initially by antisocial tendencies and pride, he exhibits a blunt, harsh demeanor, keeping others distant. Beneath this princely exterior lies a straightforward personality, and he shows generosity to close associates, though his naivety and inexperience often result in careless or shortsighted decisions.

Raised to inherit the throne, Julius faces significant pressure from royal expectations. He rejects his politically arranged fiancée, Angelica Rapha Redgrave, to pursue Marie Fou Lafan, a viscount's daughter, a decision contributing to his eventual abdication. Other characters frequently view him critically, including his mother Mylene, who shares the perception of him as hypocritical and foolish.

His development involves relinquishing his crown prince title, altering his role within the kingdom's hierarchy. A connection emerges through Marie, revealed as the reincarnation of Leon Fou Bartfort's sister from another world; consequently, Julius becomes linked to Leon's family. Marie's daughter from her previous life is reincarnated as Julius's sister, further complicating his relationships and standing.

Julius participates in key conflicts, such as mech battles against Leon, where his strategic decisions and personal shortcomings are highlighted. His story reflects themes of duty versus personal desire within the kingdom's decadent and politically fraught court.