Joel is a young boy, approximately ten years old, who serves as the catalyst for the central events of the story. He first appears at the home of the three Shimabara sisters in Tokyo, bringing news from their long-missing older brother. Hailing from the small, fictional South Pacific island kingdom of Barou, he is the son of that brother and a native Barouan woman named Juliel, which makes him the nephew of the three sisters.

In terms of appearance, Joel is recognizable by his long hair, which he wears in a single braid. He is almost never alone, as he is constantly accompanied by a small, white, dragon-like creature. Despite his youth, he acts as an emissary, inviting the Shimabara sisters to travel to Barou. It is there that he reveals their inheritance: following the death of their brother, they are the rightful monarchs of the island and, by extension, the masters of its guardian god, Neo Ranga.

Joel's primary role in the story is that of a messenger and a guide. He is responsible for awakening Neo Ranga from its slumber and for linking the sisters to their destiny as the keepers of the god. His motivations are tied to the traditions of Barou, as he seeks to fulfill the island's customs regarding succession and the protection of its deity. Throughout the series, he remains a steadfast, if occasionally passive, presence, often observing the chaos and destruction caused by Neo Ranga in Tokyo rather than actively participating in the sisters' daily struggles.

His most significant relationships are with the three Shimabara sisters. As their nephew, he shows a respectful loyalty to them, particularly to the eldest sister, Minami, and the middle sister, Ushio, who are most involved in the practical and moral dilemmas of controlling a giant god. The small white dragon that accompanies him is a near-constant companion, and the two are seldom apart, though the creature's precise nature and abilities are not extensively detailed.

Regarding his development, the series offers little in the way of a personal arc for Joel. His character remains largely consistent from his first appearance to the last. While he is the initial instigator of the plot, the focus of the narrative shifts to the sisters and their interactions with their god, leaving Joel in a supporting role. He is often present during key events, serving as an observer and a reminder of the sisters' connection to Barou. It is suggested that he acts as a narrator for the story, framing the events that unfold from his perspective.

In terms of notable abilities, Joel possesses no supernatural powers or combat skills. His most significant ability is his connection to Neo Ranga, as he is one of the few people who can communicate with or command the god. He also demonstrates a precocious understanding of the complex rituals and customs of Barou, which he uses to guide the sisters. His constant companion, the small white dragon, could be considered a unique attribute, though it does not demonstrate any formidable power. Joel's primary function remains that of a messenger and a living link between the world of modern Tokyo and the ancient, mysterious traditions of the island kingdom of Barou.