Kaze is a primary protagonist known as a being of immense power who awakens in the strange parallel dimension of Wonderland with no memory of his past. His original home world, Windaria, was destroyed by the entity known as Chaos. Kaze is the sole survivor of his kind, identified as an Unlimited from the world of Windaria, where all other inhabitants perished alongside their planet. The name Kaze is a Japanese word meaning wind, and his full name, Kuroki Kaze, translates to Black Wind, a moniker used by his rivals and enemies.

Physically, Kaze is depicted as a tall man with a slender build, tan skin, and long dark red hair tied back with a metal ring. He has light blue eyes and distinct facial markings, including three red triangles beside his left eye and a horizontal blue mark across his nose. His most iconic feature is the golden Magun, a powerful three-barreled gun, which encases his right arm. When not in use, this weapon remains in a cylindrical, frozen state. In combat, he loads it with special ammunition called Soil, which he carries on his belt. Kaze also wields a regular handgun in a holster on his right side and typically wears a long black cloak that covers the lower half of his face, dark trousers, and a long brown glove on his left arm.

In personality, Kaze is famously silent and taciturn, rarely speaking unless he wants something or is directly provoked. He is driven by a single-minded mission, which initially is to find and confront his rival, Makenshi, whom he calls White Cloud. Due to his amnesia, Kaze incorrectly assumes Makenshi is responsible for the destruction of his world. Outside of battle, he is often motionless and seemingly disinterested in his surroundings or the安危 of others, including the young twins Ai and Yu Hayakawa. However, this aloof exterior hides a protective nature, as he consistently ends up saving the group, particularly the twins. There is a mysterious connection between Kaze and the children; the Magun refuses to activate or fire unless they are present. He exhibits signs of caring beneath his stoic surface, showing great tolerance for the clingy Lou Lupus and demonstrating the capacity for tremendous rage and confidence when facing his enemies in combat. Kaze calls the Magun his heart and his life, reflecting its deep personal significance, and he derives his power from Soil.

The primary driving force for Kaze throughout the story is his pursuit of Makenshi, fueled by his fractured memories of his world's destruction. He travels through Wonderland alongside Lisa Pacifist, a member of an organization called the C2 Organization, and the twins Ai and Yu, who are searching for their missing parents. Despite his claims of not caring about the world or who dies as long as he achieves his goals, his actions reveal a growing investment in protecting his companions. His role in the group is that of a powerful, if reluctant, guardian whose incredible summoning abilities are often the only thing capable of defeating the powerful monsters and Lords of Gaudium sent by the series antagonist, Earl Tyrant.

Kaze's key relationships are central to his character arc. His most significant relationship is with Makenshi, whom he initially views as his sworn enemy. This is later revealed to be a tragic misunderstanding, as flashbacks show that Kaze and Makenshi were once allies who fought together against Chaos when it invaded Windaria. In that past battle, Kaze used the souls of his sister Aura, a Moogle named Kupo, and himself as Soil to summon the Gun Dragon, holding Chaos at bay while Makenshi attacked. This battle resulted in Kaze falling into a comatose state and ending up in Wonderland. Over the course of the series, as his memories slowly return, his quest for blind vengeance evolves into a more complex understanding of his past and his true enemy.

His relationship with the twins, Ai and Yu, is one of an inexplicable but undeniable bond. The Magun's dependence on their presence forces him into their company repeatedly, and he becomes increasingly protective of them, ultimately seeing them as integral to the final confrontation with Chaos. Lisa Pacifist is another key figure, and while no explicit romantic relationship is confirmed, Kaze becomes notably more protective of her as the series progresses. He also forms bonds with the Moogle and Lou Lupus, who look up to him and whose souls he later uses to fuel his ultimate summoning.

Kaze undergoes significant development as his memories return. He begins as a hollow, vengeance-driven amnesiac, operating almost on autopilot. Through continued contact with the twins and the group, he starts to question his initial assumption about Makenshi being his enemy. The climax of the series brings the full recollection of the true events on Windaria: Chaos was the destroyer, and Makenshi was his comrade. In a reversal of their first battle, Makenshi uses his own soul to restrain Chaos, while Kaze, using his own life force along with the Soil provided by Lou and Moogle, asks Lisa to fire the Magun to destroy the entity for good. His fate at the end of the final battle with Earl Tyrant is initially ambiguous, but he survives, though separated from the Magun.

Kaze's notable abilities center entirely on the Magun. This weapon is not just a firearm but a summoning tool that allows him to call forth powerful creatures and spirits from the Soil. The process of using the Magun is a ritualistic one where he selects a triad of Soil charges, typically with different elemental properties such as Steel Gray, Heat Crimson, and Lightning Yellow, which together summon a specific entity like Ixion. The Magun can also fire regular shots, but its true power lies in these summonings. The most powerful summon, the Gun Dragon, requires the user and two other souls as Soil. Kaze's status as an Unlimited makes him incredibly resilient, allowing him to survive battles and injuries that would be fatal to ordinary beings, including his initial confrontation with Chaos that left him in a years-long coma. He is also a highly observant fighter, capable of seeing through deception and locating hidden foes.