Kiawe is a student at the Pokémon School on Melemele Island and one of the main characters in the Sun & Moon series. He is a young, muscular boy with a dark tan and distinctive orange and brown hair styled to resemble fire. He typically wears red shorts with sandals and has black tattoos on his shoulders. A Z-Ring, which holds a Firium Z, is worn on his left arm, marking him as an experienced Trainer. Kiawe lives with his family on a farm at Paniola Ranch on Akala Island, including his father, mother, and his younger sister.

Kiawe is the most experienced and senior of Ash's classmates, which gives him a very serious and dedicated personality. He holds a deep respect for the old traditions of the Alola region, particularly regarding Z-Rings and Z-Crystals. This reverence stems from the fact that his own Z-Ring was a keepsake from his deceased grandfather, who was a former island kahuna. Because of this, Kiawe initially shows disapproval when he discovers that Ash received a Z-Ring from the guardian deity Tapu Koko without completing the customary island challenges. He believes that using a Z-Move requires not just power, but also the resolve and experience earned through trials. When Ash carelessly misplaced an Electric Z-Crystal, Kiawe became enraged, demonstrating how seriously he takes these sacred items.

Despite his serious exterior, Kiawe has a more playful and competitive side. He loves racing, is a skilled rider of Tauros, and enjoys friendly competitions with his friends. At home, he is a doting and overprotective older brother to his little sister, Mimo, often reacting excessively to prevent her from doing any dangerous chores. While he has a strong affinity for Fire-type Pokémon, he is less confident with Water-types, once admitting he did not know how to interact with a Popplio. His commitment to his family farm means he is tireless and strong-willed, waking up early to make milk deliveries using his Charizard and handling various chores.

Kiawe’s role in the story is as a classmate, friend, and friendly rival to Ash. He acts as a mentor figure who helps Ash understand the true meaning of Z-Moves and the culture of Alola. Key relationships include his bond with his grandfather's Charizard, which serves as both a trusted partner and a Ride Pokémon, and his Turtonator, his primary battling partner. He also has a rivalrous friendship with the Kanto region trainers Brock and Misty, showing a highly competitive side when he challenges Brock to a gym battle. As part of the Ultra Guardians, a task force formed to deal with Ultra Beast incidents, Kiawe takes on the duty of protecting the Alola region alongside his classmates.

Throughout the series, Kiawe undergoes significant development. While always a capable battler, he learns to adapt his strategies, such as when he overcame his discomfort with Water-type Pokémon by learning from his sister. His competitive drive pushes him to continuously improve, and he eventually catches an Alolan Marowak, adding a new Fire-type to his team. His journey leads him to a profound moment where, guided by the guardian deity Tapu Lele, he decides to follow in his grandfather's footsteps and aspires to become an island kahuna himself, embracing the ideal of being a user of fire that nurtures life, not one that destroys it.

Kiawe possesses several notable abilities. He is a proficient battler who specializes in Fire-type Pokémon and is highly skilled in performing Z-Moves, such as Inferno Overdrive. Beyond battling, he is capable of cooking home-cooked meals, repairing things around the farm, and caring for the Pokémon there. His strength and stamina are enhanced by his daily farm work and his early-morning routine of delivering milk by Charizard, which involves flying across distant islands. His notable Pokémon include his main partner Turtonator, his family's loyal Charizard, and an Alolan Marowak he caught later in the series.