Tokio Kurohara

Tokio begins as an indecisive teenager with little confidence in his own abilities or direction. He admires Azuma's intelligence, athleticism, popularity, and willingness to act, and has grown accustomed to letting his friend's decisions determine his own. Rather than resenting Azuma's accomplishments, Tokio initially seems comfortable regarding himself as the lesser half of their partnership.

He is nevertheless compassionate and increasingly motivated by the possibility of helping others. Becoming a Choujin forces him to make choices without simply following Azuma, particularly after meeting Ely Otta and becoming involved with Yamato Mori. His fear and uncertainty remain important parts of his personality, but he gradually learns to act despite them.

Time spent training and working away from his old life makes Tokio considerably more independent. He becomes willing to disagree with people he once automatically followed and develops the resolve to make difficult decisions according to his own judgment rather than measuring himself against Azuma.

Tokio is a Beast Choujin whose abilities are modeled on a vulture. Beastification enhances his strength, speed, reflexes, eyesight, and durability, while Partial Beastification allows him to transform selected portions of his body without maintaining a complete transformation. He eventually develops large wings capable of sustained flight and can communicate with birds.

Full Beastification transforms his entire body into a humanoid vulture form and greatly increases his physical abilities. Like other Choujin, Tokio can use Raise to recover from otherwise catastrophic injuries by effectively reconstructing his body, although repeated use places considerable strain on a Choujin.

Tokio later manifests the Adamantine Harpe, a specialized weapon particularly dangerous to Choujin because wounds inflicted by it interfere with their ability to Raise. He also develops much finer control over his Beastification, wings, feathers, and Chaos state through intensive training.

Tokio's transformation begins when he and Azuma are confronted by criminals who have become Choujin. Desperate to obtain enough power to fight back, the two inject themselves with the same drug, but Tokio is the only one who initially displays an obvious transformation. His new existence brings him into contact with Yamato Mori, where Ichiiro Sato, Simon Kagomura, and Maiko Momoma help introduce him to the wider Choujin world.

His early development revolves around learning what he wants to do with his power. Tokio begins helping Yamato Mori while continuing school, and his growing independence creates tension with Azuma, whose identity had long been intertwined with being the more capable of the two friends.

Their suppressed insecurities eventually erupt into a violent confrontation after Azuma awakens as a Choujin. Tokio's own Chaos transformation allows him to overpower Azuma, forcing both boys to confront the unhealthy imbalance that had existed within their friendship.

Tokio later leaves his familiar life behind for extended training and field work, returning as a far more capable Keeper. His unusual potential, connection to Zora's power, and developing foresight increasingly place him near the center of the struggle over the prophesied destruction of Yamato.

Azuma Higashi is Tokio's childhood friend and the person he admires most at the beginning of the story. Azuma repeatedly protected Tokio from bullies, while Tokio grew accustomed to following Azuma Higashi's lead. Their friendship becomes strained when their respective insecurities surface after both become Choujin, culminating in a fight that forces them to acknowledge the imbalance between them.

Ely Otta becomes one of Tokio's closest friends after they meet as newly awakened Choujin. Tokio and Ely Otta train and fight together through Yamato Mori, developing an easy partnership despite their contrasting personalities.

Ichiiro Sato becomes an important instructor in Tokio's development as a Choujin. Under his demanding training, Tokio develops far greater control over his Beastification and combat abilities.

Simon Kagomura initially approaches Tokio as part of Yamato Mori's response to his awakening and later becomes a fellow Keeper and combat companion.

Maiko Momoma similarly becomes one of Tokio's allies within Yamato Mori and participates in his early training.

Sora Siruha takes a particular interest in Tokio because of his potential. Her belief that he may play a decisive role in the future places Tokio directly within the conflict surrounding the Beast of Prophecy and the approaching calamity.