Kujo was born in the Yugata Temple, the product of an affair between one of the Spirit Warriors and a temple priestess. Due to his parentage, he was scorned and belittled by the other Spirit Warriors and inhabitants of the Temple, as well as the children who would go to the Temple for training. Despite this, his father managed to convince the Temple leaders to let him live at the Temple, albeit as a lowly servant.

Because of the way others treated him, Kujo became very bitter, causing him to occasionally lash out. During one such time, Kujo's emotional state affected his spirit, allowing him to unwittingly harness its power. Kujo was ten years old at the time. After seeing this display of power, Kujo's father requested that he be trained as a Spirit Warrior, explaining that the "fire of his spirit burns bright." His request was denied.

Kujo's father did not accept defeat, however, and elected to train the boy himself in secret. Kujo quickly proved to be a capable pupil, mastering the katana and learning how to control his spirit power to some degree. However, his training was cut short when the Temple leaders found out about his secret training sessions. Kujo was sixteen. His father was exiled to wander the Eretejva Tundra, while Kujo was kept in a small cell, only being let out to do his servile duties.

After deciding he was done being a slave, Kujo managed to break out of his cell, barely escaping the Temple and heading south, travelling mainly between a few settlements and villages located relatively close to the Tundra, mostly picking up mercenary work wherever it could be found. Kujo made numerous attempts to enter the Tundra in search of his father, but has so far been unsuccessful, quickly being forced to turn back everytime due to the extreme temperatures and his lack of supplies. He vows to one day discover the fate of his father, whatever that may be...