Hachimon is a Tanuki demon who is the friend, servant, and accomplice of Miroku. Named after the Japanese god of war. Hachimon usually acts quite cowardly and is reluctant to put himself in danger. Despite that, he often seems to arrive just in time to save people or provide transportation at a critical time. Referred to by his nickname Hachi in Inuyasha, he appears infrequently throughout the storyline. His main role is comic relief, transportation, and most often as a plot device. Although it’s never implicitly stated, Hachi lives either in or near the temple of Mushin, Miroku‘s Foster father and mentor. In his first appearance along with Miroku, the two are pulling a scam where Hachi pretends to be a marauding yokai that Miroku drives off. Having “saved” people in distress, Miroku would then collect his reward.
Hachi’s only exhibited power is transformation. Like Shippo, Hachimon can use a leaf to transform himself into a variety of things. His first transformation shown was to become a giant yellow rock on Miroku‘s orders so that he could snatch Kagome and her bike while Inuyasha was distracted. Hachi is also able to transform into a giant yellow blimpish tadpole sort of thing, a form which he uses to transport people by having them ride on his back. Hachi is not limited to transforming into objects though. We’ve seen him transform into Miroku in order to pull a scam selling fake seals and getting girls. He’s also transformed into Kagome to drunkenly sing along with a drunk, transformed Shippo and Kagome.