Otaku serves as God's perpetually loyal younger brother, shadowing him throughout most events. He endures God's frequent scolding and physical aggression without wavering in his devotion. While Otaku consistently follows God's lead, subtle cues indicate his private disapproval of many of God's selfish choices. He rarely takes independent action to challenge or openly oppose God's behavior.

His personality isn't inherently malicious, yet altruism rarely motivates him. During downtime, he almost invariably occupies himself with a handheld video game console, prioritizing this pastime above other activities. Otaku develops a romantic interest in O-Jou, a girl within their group. This desire fuels a direct rivalry with Ben, another child vying for O-Jou's affection. Consequently, Otaku displays active dislike toward Ben, driven solely by their competition for O-Jou's attention.

Throughout the series, Otaku's core traits remain unchanged: steadfast loyalty to God despite underlying reservations, self-absorption, dedication to gaming, and persistent rivalry with Ben over O-Jou. Details about his background, family beyond his brotherhood with God, or life prior to the group's arrival on Noah are absent. His portrayal is confined solely to the original 1995 television series, with no documented appearances or developments in other official media.