|Occupation||Second Prince of New Yogo|
|Novel||Moribito: Guardian of the Spirit|
Chagum is the second prince of the Imperial Family, who unexpectedly becomes the host of the egg of the water spirit. He is one of the main characters in the series, featuring as the protagonist of the Tabibito ("traveler") strand of the novels.
During Moribito: Guardian of the Spirit, Chagum is introduced as the Second Prince of New Yogo, the son of the Mikado by the Second Queen. Out of concern for the strange development in her son's body, the Second Queen consults the Star Reader Shuga and the magic weaver Torogai. When the Star Readers suspect that Chagum's body houses the reincarnation of the water demon his ancestor, the first Mikado, defeated, the Mikado arranges for the Second Prince to be secretly assassinated to save the country.
In order to protect her son, the Second Queen hires the spearfighter Balsa to protect the prince for the rest of his life. With Balsa as Chagum's bodyguard, they manage to elude the assassins after his life and learn the true nature of the entity within him - it is actually the egg of a water spirit that must be born to prevent a terrible drought while the actual demon his ancestor defeated had sought to consume the water spirit's egg.
As Balsa and their friends try to find a way to remove the water spirit's egg from Chagum, the young prince lives the life of an ordinary boy and gradually matures into a sensitive and insightful person. During his time with Balsa, he becomes deeply attached to her and trusts her to protect his life.
Chagum is a young boy, approximately twelve years old at the beginning of the series. In the anime, he is depicted as having long dark hair that is cut early in the series in order to conceal his identity as the Second Prince. Throughout the year he spends with Balsa, he grows taller, which Torogai notes when she reunites with Balsa and Chagum at the end of winter before the impending birth of the water spirit.
Chagum's clothing changes several times due to the nature of his character. Upon his introduction, he wears royal garments, with long hair styled into a bun and pigtails, and a golden crown. The garments are discarded in favour of commoner's clothing, consisting a dark blue robe and grey pants, after escaping the palace. For the final battle against the egg eater, Torogai presents Chagum with more warrior-like clothing, which also depicts motifs of the Yakoo. When he returns to the palace, Chagum wears royal clothes again, and dons a single hair bun and a new crown.
Back at the palace, Chagum was very close with his mother, the Second Queen. His relationship with his father, the Mikado, seems to have been more distant, but even after he calls for the assassination of Chagum, the boy is not ill-spirited towards him. In the anime, Chagum's deep respect for his father is illustrated when he becomes infuriated at an aggressive boy from Rota for insulted the Mikado. Despite his aloofness, the Mikado privately cares for his family and when it is believed the assassination has succeeded, the Mikado orders Chagum to be honoured as a hero rather than be remembered as a pariah. The anime also depicts Chagum possessing a close relationship with his older brother, Sagum.
Throughout the series, Chagum develops a strong bond with Balsa. Though he sometimes rebels against her, he also holds her in high esteem, and she is like a mother to him. Chagum comes to trust her implicitly and despite the fear he holds for his fate as the host of the water spirit, believes that Balsa will find a way to save him. Chagum becomes close with many of the people he meets during his time with Balsa; these include Tanda, Toya, Saya, and Torogai. Toya takes on an "older brother" role for Chagum and helps him adjust to life as a commoner.