Kiawe is a student at the Pokémon School on Melemele Island and one of Ash's classmates in the Alola region. He lives with his family, including his parents and his younger sister named Mimo, on a ranch in Paniola Town on Akala Island. Before coming to the Pokémon School, Kiawe was inspired by his late grandfather, who was the former king of Akala Island and a fire dancer. His grandfather taught him that fire should be a force that nurtures life rather than one that destroys it, imparting to him his Charizard, Z-Ring, and Firium Z as keepsakes.

Personality-wise, Kiawe is the most serious, disciplined, and experienced battler among his classmates. He is rigorous in his training, often practicing at night, and has a deep respect for the importance of Z-Moves and the traditions of the Alola region. He once became furious with Ash for being irresponsible after Ash lost his Z-Crystal, and his anger is known to be feared by others. Despite his often stoic and stern appearance, Kiawe has a warm heart and can become easily emotional or hot-blooded, whether he is deeply moved by a concert or fiercely competitive in a Pokémon baseball game or relay race. He is also extremely protective of his younger sister, constantly preventing her from lifting heavy objects, though he finds it difficult to refuse her requests.

Kiawe's primary motivation is to become a trainer worthy of his grandfather's legacy and to master the traditional fire dances of Alola. He takes his responsibilities seriously, balancing his school life with work on his family's farm and making deliveries across the Alola archipelago on the back of his Charizard. He is fascinated by Fire-type Pokémon above all others and dreams of becoming a professional fire dancer.

In the story, Kiawe acts as a knowledgeable mentor figure to the less experienced members of the group. He is often the voice of reason and has helped his friends with their training, such as assisting Ash in mastering a Z-Move and helping his classmates' Pokémon learn new attacks. He owns a Z-Ring and is capable of performing powerful Z-Moves like Inferno Overdrive.

His key relationships form a core part of his character. He has a strong bond with his family, especially his sister Mimo and the memory of his grandfather. Among his classmates, he is respected for his strength and maturity, though his competitive fire emerges during the various school activities and challenges. His relationship with his own Pokémon is also central; he received his Charizard from his grandfather as a gift for transportation, uses his powerful Turtonator in battles as a competent fighter, and captured his Marowak only after chasing it down for stealing a festival crown, noting that Marowak shares his own hot-headed nature.

Kiawe shows development throughout the series, as seen in his decision to eventually succeed his grandfather as the king of the new island, accepting the weight of that responsibility. His journey also involves learning to balance his fiery passion with the wisdom of using fire to nurture life, a lesson passed down from his grandfather.

In terms of notable abilities, Kiawe is a highly capable Fire-type Pokémon trainer with considerable combat experience. He is proficient in performing Z-Moves using his Z-Ring and specialized in Fire-type Z-Crystals. His training methods are strict and dedicated, and he is shown to be physically strong and fit, reflecting his active lifestyle working on the ranch and practicing dances. He also demonstrates skill in traditional Alolan dancing, which is connected to his fighting style and command of Fire-type Pokémon.