Kohaku is Sango's younger brother. Kohaku killed all of the youkai exterminaters in his group when Naraku plotted to destroy their village for the shikon jewels they had. Kohaku almost killed Sango in the process, but Sango survived. Naraku kept Kohaku alive by using a Shikon jewel in him, and uses him to toy with Sango and the groups emotions, at one point coercing Sango to steal Tetseiga from Inu Yasha.
Myoga-jiji ( Myoga-jichan)
Myoga the flea is Inu Yasha's right hand man so to speak. He was a friend of Inu Yasha's father , the great dog youkai. Myoga is smart and helps out, but dissapears in the face of danger. Where ever he goes is often felt to be the safest place to be.
Kirara is Sango's friend and companion. She's a kawaii little youkai that looks like a fox..but then again Shippou-chan looks like a fox..hmm.. ne ways, she can transform into a larger version of herself, and has larger teeth (like the tiger from the Flinstones) and more tails, and her paws are firy..and she flies. its aweseome. In one episode it hints towards the fact that she may have been the companion of the powerful miko responsible for the creation of the Shikon no Tama.
Naraku is an evil hanyou. He is the result of the bandit Onigumo, who Kikyou once helped nurse some 50 years ago. He invited demons to eat him and make him a new body, one that was invinsible. However, no matter how many times he changes bodies, he always has a small spiderlike scar on his back, the last remains of Onigumo. Naraku is the one who set everthing in motion. He pretended to be both Kikyou and Inu Yasha 50 years ago and pit Inu Yasha and Kikyou against eachother, resulting in Kikyou's death, and Inu Yasha's death like stasis on a tree. He hunts for the Shikon no Tama and creates his own little serrogate family of evil..
Kaede is Kikyou's younger sister. She has an eyepatch on her eyes, and as of yet no explanation as to what happened. Something had to have happened between Kikyou nursing on Onigumo and Kikyou's death because u see no covered eye by then. She is the medical woman and a miko as well, but not very powerful. She is still "under the sisterly thing" when Kikyou is around and respects her still.
Rin is a little girl who lost her entire family.She found Sesshomaru in the forest right after his battle with Inu Yasha, where Inu Yasha used the Kaze no Kizu to kick his furry butt. But the Tenseiga saved him,and here he was. Rin offered him food, and though he didn't take it, his heart was lightened by the fact someone cared.Later,she was killed by the wolves of the wolf-demon tribe controlled by Kouga-kun. Sesshomaru came back and found her, and felt compassion. *gasp*. He saved Rin from the underworld minions with the Tenseiga, and now Rin follows him everywhere, little by little healing Sesshomaru's heart of hatred for humans. Also, she annoys the crap out of Jaken, which is so awesome.^-^
Jaken is a little toad like youkai that follows Sesshomaru and refers to him as Sesshomaru Sama. Its quite sad really, becasue Jaken is just a lacky. He's a yes man, and knows it. He is constantly put in harmful situations, abandoned by Sesshomaru, and finds it scarier when Sesshomaru smiles than when he gets mad. He has a two-headed stick..that i forget what it does, but they used it in finding Inu Yasha and Sesshomaru's father's grave. Sometimes u pitty him, other times u wanna kill him, other times you want Sesshomaru himself to kill him.