The city is located near the center of Zhao. It is close to a city called Gyou. Kantan's royal entrance is covered by the city of Retsubi, very significant for its defensive stability.
Kantan is the home of general Ko Chou, who goes with the name "Guardian Deity of the Royal Capital". There is no further information about him or regarding his action both present and past.
Great General Ri Boku of the three great heavens requested Ko Chou to move towards the region of Koku You. So that they can repel the invading Qin army with all the strength they have. King Tou Jou was undisturbed by the dire news of the invasion, while Kaku Kai told the desperate Ko Shuu to not disturb the king during his rest. Actually, Kaku Kai was angry due to Ri Boku's actions, regarding of Qin army's changed directions and regarding of Gyou and Kantan military defenses.
Before the storyline of the Kingdom manga
Ei Sei, the Queen Mother and Shi So were prisoners in the capital. They were hated by the citizens due to the incident in Chouhei; thus Ei Sei was traumatized by the hate of all Zhao denizens and by his mother's hatred. Ei Sei lived there for nine years before he was rescued by Shi Ka and started living in Qin.