Unlike other Amazons, he was raised as a human and is described as a "farm-raised" Amazon. Throughout the story, he transforms into Amazon Omega to hunt other Amazons. While struggling between his instincts and his humanity, he finds his own way of life: "protecting what he wants to protect."

Formerly a cell biologist at Nozama Pharmacy, he is a human who became an Amazon "artificially" by transplanting Amazon cells into his own body. He transforms into Amazon Alpha to hunt Amazons. He has the personality of a wild, openhearted mad dog with destructive convictions. Though wild and defiant, he possesses a clumsy kind of love.

A half-Amazon, half-human hybrid. Born with an intense urge to eat humans, he loathes himself as a "monster." Though fundamentally a kind-hearted boy, he constantly suffers from hunger and loneliness, desperately searching for a place where he belongs. He transforms into Amazon Neo to hunt Amazons.

Formerly human, she was killed by her father after he turned into an Amazon, then resurrected by Nozama Pharmacy as a weapon (Amazon) based on her corpse. She transforms into the Crow Amazon. Lacking emotions or the sensation of pain, she is a "living doll" who mechanically hunts Amazons according to orders. While spending time with Chihiro, she begins to show faint fragments of past memories and emotions.