Kai (介, Kai; "Meditation") is the personal summon of Kouhei Hakoda and the friend of his partner, Hei. He is the chief of all the bird-type summons, as all naturally born Dragon Hawks are. Despite being a Hawk, he is often labeled as a eagle, a bird species similar to the hawk. Kouhei and Kai have a long history together, with Kouhei raising Kai when he was a chick, and grew up with him. Kouhei was said to have named him Kai simply because of the kanji look; it looked similar to an arrow pointing upwards, and Kai could fly. Despite protests to change the name, it has stuck, and he is known as Kai to this day. He does not speak to Kouhei until first summoned to Kouhei.