Chiriko's intelligence actually derives from his role as a Celestial Warrior and when his character disappears, he becomes a rather average child with limited intelligence. This limitation on his powers alongside being the youngest and physically weakest in the group is a source of frustration for Chiriko. He is particularly sensitive about his height and his peculiar intelligence and strives towards becoming a "man of strength", but is otherwise a quiet and good-natured student. Since a very young age, Chiriko has held a strong interest in research and has amassed a great deal of knowledge through books and study.
Though somewhat unusual, Chiriko develops a strong relationship with Tasuki, who happily accepts the role of an older brother figure to Chiriko and is particularly devastated when Chiriko dies. The youngest Celestial Warrior's death comes when his body is possessed by Seiryū Celestial Warrior Miboshi. After regaining control of his body, Chiriko stabs himself, taking Miboshi with him in death.
In Fushigi Yûgi Eikoden, Chiriko is revived as Gakuren, a child of a politician. Despite being still an infant, he is capable of speech and is the only character to remember who he is in the first place, but has to fully revive quickly or will be reborn as a normal boy.