Chako is a red Kishu Inu with two tiny black spots between her eyes. She wears a collar.
She is portrayed in a bit shallow manner, as she is only interested in manly males with high status.
Chako's owner rescued Sasuke from the road and took him to Ōu in a car. Sasuke developed a crush on Chako during the ride and lied to her that he is one of the officers of Ōu's army. Later Yūsuke, Yūji and Hiroshi arrived to Chako's home village and forced the pet dogs to give them food. Yūsuke had a thing for Chako.
Chako and Koyuki hear from Kansuke that Yūsuke's gang plans to kill Kotetsu who ran away from home, so the sisters go search for him. They find Weed and Kotetsu fighting against the gang. Chako runs to tell Ōu's army about it, but Yūsuke sends Hiroshi after her. She tries to lose him by hiding on the river, but she is spotted. Luckily Weed shows up, rescues Chako and drives Hiroshi away. After Yūsuke's gang is driven away, Chako, Koyuki and Kotetsu spend the night with Ōu's army and then return back home. Chako meets with Sasuke a few times, but later she hears that he lied to her and gets upset. She is not seen again after this.
- She shares the same mother as Koyuki and Kotetsu, but not the same father.
- She was believed to be half Shiba Inu by some fans, due to her resembling her crush Sasuke in colour, but there is no proof of that in the manga. Plus, Kishu Inus can be red just like the all other Japanese native dog breeds.