Sora is one of two brothers raised by dugongs, granting him unique aquatic abilities for comfortable marine life. His origins are largely unexplained, but he shares an intrinsic link to supernatural phenomena affecting global seas—mass fish disappearances and celestial events like a comet plunging into the ocean. He displays initial coldness, bluntness, and arrogance, particularly in condescending and hateful early encounters with Ruka Azumi. This demeanor gradually shifts into genuine concern and care as their relationship evolves.

Strong-willed and introspective, Sora often drifts into deep thought. Possessing a degree of foresight, he anticipates his own mortality. He prepares for it by entrusting Ruka with a meteorite, instructing her to deliver it to his brother Umi at the right time. This act underscores his sacrificial love for Umi, with whom he shares an exceptionally close, protective bond. Sora willingly risks his life to save Umi, demonstrating the depth of their fraternal connection.

His character development centers on evolving relationships: transforming hostility towards Ruka into trust and guardianship, and maintaining unwavering, selfless devotion to Umi. Sora's role is intrinsically tied to the oceanic and cosmic mysteries central to events where the brothers' fates intertwine with celestial rebirth and the interconnectedness of life. While broader mythological context exists in the source manga, the narrative emphasizes their symbolic roles within the natural world.