Karas tells the story of Yousuke Otoha, a former yakuza, living in a fictional version of Shinjuku, Tokyo populated by humans and yōkai (Japanese spirits). He is one of the titular karas, humans appointed as superpowered agents of the land. Able to transform into a car, an aircraft, and an armored crusader; the skilled swordsman is to stop his corrupt predecessor, Eko, from taking over Tokyo. Supporting characters such as Eko's former henchman, Nue; the yōkai; and Homura, the karas of another city, help Otoha in his quest. A concurrent side story focuses on humans affected by Eko's scheme.
Tokyo: a city populated by both humans and ghostly beings. They exist in both dimensions, seen and unseen: spirits, apparitions, demons. The balance between these two dimensions has long been upheld by the city's guardian crow Karas and his masters. But that balance has been thrown into disarray as Eko, a former Karas, has attempted to seize power and bring order to the streets through force. The entity Yurine, who represents the will of the people, stands in his way with her newly risen Karas. Now an ageless battle stretching across both dimensions and killing humans and spirits alike is in progress. Karas is humanity's last hope.
Karas: The Revelation is about the battle between supernatural forces on the streets of modern-day Japan. The Revelation covers the true identity of newly-minted Karas (spiritual protector of humanity from demonic forces) Otaha, who returns to his hometown to rescue a friend from gangsters. Meanwhile, evil Karas Eko continues his campaign of terror against mankind with the aid of a multi-headed dragon summoned by the powers of rogue demon Nue.
