Geran is the king of the castle of the sun, a prominent figure in the world where the series takes place. Known to be a natural-born leader, his personality is defined by a strong and assertive manner; he clearly states his opinions and generally maintains a positive, forward-looking attitude in any situation. As a competitive individual who dislikes losing, he frequently compares himself to those around him, which can lead him to stubbornly push himself to win. Despite his strong-willed nature, Geran has a notable vulnerability to flattery, which can cause him to trust others too easily and potentially be taken advantage of.

A significant aspect of his background and motivation is his deep admiration for the manga artist Rumiko Takahashi. This admiration manifests in his primary hobby: collecting the autographs of celebrities. Within the narrative, he serves as one of the many varied and colorful inhabitants who interact with the central character, with his own idiosyncrasies contributing to the dynamics of the group. While detailed information on his specific development throughout the series is limited, his role as the Sun King places him as an established figure within the story's setting. His key relationships are with the other residents of Meruhen, where his personality and hobby likely influence his interactions. In terms of notable abilities, his primary characterization focuses on his leadership qualities and social traits rather than physical or magical powers.