Raki is an ordinary human boy whose life is permanently changed when a Yoma destroys his family. He comes from the village of Doga, also called Lautrec, where he lived peacefully with his relatives, including his older brother Zaki. The Yoma that attacked his home disguised itself as Zaki after killing him, and the creature was only defeated when the warrior Clare arrived to hunt it. Clare saved Raki's life, but the villagers then drove him out, fearing that his close contact with the Yoma might have corrupted him. With nowhere else to go, Raki followed Clare, and she eventually allowed him to remain at her side as her traveling companion and cook.

Raki's personality is defined by warmth, empathy, and stubborn loyalty. Unlike most people in his world, he does not judge Claymores or even Awakened Beings, and he forms genuine bonds with beings that others would fear or hate. He is highly perceptive about the emotions of others, able to see Clare's true self beneath her cold and guarded exterior, and he also understands that Priscilla quietly longs for death. He is not naturally brave at first, and early on he is paralyzed by fear when faced with a Yoma, but his courage grows through his devotion to the people he loves. He is determined to help and protect others even when he lacks the physical strength to do so.

His motivations begin with grief and the need for safety after losing his family, but they quickly transform into a desire to repay Clare and to become strong enough to stand beside her. He wants to fight and protect her in the same way she protected him. Over time, his purpose becomes less about self-preservation and more about devotion, hope, and being a source of emotional support for Clare.

In the story, Raki serves as the human perspective in a world dominated by superhuman warriors and monsters. He acts as Clare's emotional anchor and moral compass, reminding her of what she fights to protect and helping her hold on to her humanity. He travels with her through their early adventures, and after they are separated, his journey continues independently. He falls in with Isley, the powerful awakened being of the north, and trains under him to become a swordsman, eventually wearing armor and wielding a two-handed sword. He later travels with a regressed, childlike Priscilla, caring for her while knowing her true nature and accepting the risk that she might give in to her hunger, in which case he would try to stop her even though he acknowledges he would likely fail.

His key relationships shape his development throughout the story. His bond with Clare is the most important, growing from gratitude into deep love and mutual devotion. His friendship with Priscilla is unusual and compassionate, as he treats her kindly despite the danger she represents and understands her hidden desire for peace through death. Isley serves as his sword master, giving him the combat training that allows him to move from a helpless child toward a capable young man. His deceased brother Zaki remains significant because the Yoma's impersonation of him is the event that set Raki's entire journey into motion. He also recognizes the importance of Teresa in Clare's past and understands Teresa's sacrifice, even though he never meets her.

Raki's development across the story is one of steady growth from fear toward courage and from dependence toward purpose. Early in the series he is a cowardly orphan who freezes at the sight of monsters, but by the later stages he becomes a young man who is willing to face overwhelming threats, including Priscilla in her most terrifying forms, without abandoning his principles. He learns to accept his limitations as a human with no special powers, and finds meaning in his loyalty, empathy, and emotional resilience rather than in martial strength alone.

In terms of notable abilities, Raki has no supernatural gifts. He begins the story with no combat skill whatsoever, but under Isley's tutelage he becomes a trained swordsman capable of wielding a large two-handed blade. His greatest strengths remain his emotional intelligence, his ability to see into the hearts of others, and his willingness to endure danger and hardship for the sake of those he cares about. He also survives circumstances that would kill most ordinary humans, including an injury from a weapon contaminated with awakened being tissue, which threatens to transform him; he is only saved through Priscilla's intervention. Despite everything he endures, Raki remains a fundamentally kind and hopeful person, and his presence gives the people around him a reason to preserve their own humanity.