Mayoi is a fifth-grade elementary school girl. She is 144cm tall and always carries a big backpack, wears a hairband, and sports ponytails. Befitting her age, Mayoi is cheerful, energetic and inquisitive. She makes a lot of spelling mistakes and has a habit of mispronouncing Koyomi's family name. On the other hand, she does not easily trust strangers, and will even fight back against them if they become too nosy. Ten years ago she was involved in a traffic accident and died because of it. After that she became a ghost and considers herself a "lost snail". She unwillingly causes the people around her to become lost and unable to find their way home. The only people who can see her are people who don't want to go home in the first place. However, after Araragi and Senjougahara help her find the home she was looking for, she changed from an "earthbound spirit" to a "wandering spirit", a fact that she considers to be a bonus, as well as granting her to be free to wander wherever she desires. At the end of Nisemonogatari, she said goodbye to Koyomi, implying that she will not be seeing him again, which will be the basis of the next story, Mayoi Jiangshi. Her family name before her parents got divorced was Tsunade. In Shinobu Time, she is chased by the darkness together with Koyomi Araragi. It is later revealed by Izuko Gaen that the darkness was targeting Hachikuji because she remained in the town even after she was saved by Koyomi. To stop the darkness, she finally decides that she must pass on. She kisses Koyomi and confesses her love for him before she vanishes.
The young leader of a yourouzoku (youkai-wolf tribe), Kouga wishes to avenge his fallen comrades who were slaughtered by Kagura, one of Naraku's minions. While brash and arrogant, he is shrewd enough to run from a fight if he thinks he can't win. He has a shikon shard in each of his legs which make him stronger and faster. Although he bickers with InuYasha constantly, when one of them is in danger, the other will lend a hand. He considers Kagome his woman, which irritates InuYasha to no end. Koga constantly confesses his love towards Kagome but Kagome does not share his affections, only having eyes for InuYasha. As the series goes on, Koga lets up on his affections for Kagome gradually. Eventually, in chapter 466 of the manga, he leaves her behind with the statement "if InuYasha ever starts getting on your nerves, you can come to me." ("Koga" means "steel fang.")
Hakkaku is the other of Koga's followers. He has a white mohawk, chain armor, and a fur hide. His name is never really said in the manga. (Source: Wikipedia)
Mouryoumaru is an enemy of Naraku, despite being indirectly created by his powers via Hakudoshi. He is a 100-foot long demonic golem who can shoot blasts of energy from his arm. At first, he is merely a life force puppet made from youkai, lacking any true personality, soul or will. Kanna places The Infant inside him, giving Moryomaru Naraku's physical life force. Moryomaru increases in power as he absorbs different youkai to gain their abilities, and nearly defeats a combined onslaught of most of Naraku's enemies, including Kikyo, Kohaku, Kagome, InuYasha, Miroku, Sango, Shippo, and Sesshomaru. He succeeds in breaking Sesshomaru's sword, but flees after nearly losing a shard of the Shikon Jewel. He is killed when he devours Naraku, and Naraku absorbs his power from the inside and uses it to be reborn.
Hitomiko was a priestess that Naraku tried to kill in her childhood, but due to her strong spiritual powers he failed. It was said that her spiritual powers could be compared to Kikyou's powers. Eventually, many years later Hitomiko is finally killed by Naraku. He ressurrects her in order to use her to destroy Kagome, controlling her mind and body, but most of the times due to her strong powers Hitomiko resists and tries to spare and help Kagome.
Highly decorated and a Knight of the Order of the Garter, the Admiral is Robert Stephenson's main point of contact with the British Government. The Admiral is rather set in his ways, believing that men, not machines, fight wars. He displays a stereotypically British style of composure, calmly taking afternoon tea on the deck of his flagship while a battle rages nearby.
An oddly-colored spider with three eyes upon its abdomen, which appears in the sunset world where Ai and her assistants reside between assignments. It speaks with the voice of a man and is apparently Ai's superior, having been the one to pronounce sentence on her after she killed the people of her village.