Ko is one of the canines that form the eight Satomi Canine Warriors. He, along with the other Canine Warriors, defends Taka Pass and Kusa Village under the Satomi House, led by Princess Fuse. Ko is a Rough Collie whose fur color are of varying shades of brown. He wears a purple bandanna around his neck with the Orb of Wisdom attached. He has long straight fur and tall, slightly tip-drooped ears.
Prior to Amaterasu's visit to Kusa Village, Ko temporarily separated from the rest of the Canine Warriors to pursue his own needs. When Amaterasu is tasked by Fuse to locate the warriors within the village, Ko is found in a cave above the village only accessible by Vine. Once fed, he will return to Princess Fuse.
Ko and the other members of the Kusa 5 are encountered in the Playhouse after the defeat of Sen and Ryo. Ko has some stage decorations on him, and he is excited for his performance, but a stagehand thought that he was just imitating the script.
After defeating Ninetails, Amaterasu can challenge the Canine Warriors, renamed Kusa 5, at the Gale Shrine for Stray Bead #35. Ko appears with Rei, Shin, Chi, and Tei, sharing the same attacks. When the battle starts, Amaterasu can immediately approach him and begins her assault with farming techniques. After the farming procedures are completed, Amaterasu has to focus on offense while simultaneously defending from the attacks of the other Canine Warriors. When Ko jumps into the air and perform a somersault before landing, his Wisdom Orb glowing, Amaterasu has to run to a certain distance, wait for Ko to lunge at her, and when he has covered half the distance between his original position and Amaterasu's, execute a Sub-Reflector Counterattack to gain a Demon Fang and defend from the attack. Other attacks of the Canine Warrior includes a series of multiple lunge and bites, a hole-digging attack, and a land mine attack. When sufficient damage is dealt, Ko will be stunned, a chance for Amaterasu to deal further damage.
- He and the other canine warriors represent eight virtues of Confucianism.
- In Confucianist thought, filial piety (kō) is the correct relationship between the superior and the inferior in the mark of the social hierarchy.
- Ko is a Rough Collie, a type of herding dog from Scotland.