Amaru Ryudo, the 13-year-old youngest brother among four descendants of the Chinese Dragon Kings, holds the mantle of the Black Dragon King of the Northern Oceans, commanding dominion over water and lightning. Though his youthful demeanor initially suggests fragility, his latent abilities grow indispensable to his siblings as their conflicts intensify. His quiet strength emerges in pivotal battles, aiding his brothers in both human and draconic forms.

Gentle and introspective, Amaru contrasts his impulsive third brother, Owaru, whose companionship he cherishes. While he admires Owaru’s boldness, he leans on the wisdom of his eldest brothers, Hajime and Tsuzuku, relying on their guidance even as he begins to forge his own path. This balance of reverence and budding autonomy shapes his evolving role within the group.

Amaru’s dragon lineage surfaces through prophetic dreams—visions deciphered by Hajime to anticipate threats. These glimpses into fate highlight his profound connection to ancestral power, though mastering such forces strains his youthful resolve. Early hesitancy in battle gives way to strategic prowess, culminating in decisive moments like the clash against Gozen of Kamakura, where his dragon form tips the scales. His journey traces a shift from guarded reliance to self-assured action, navigating the dual burdens of mortal adolescence and the ancient legacy he must uphold.