Hachimon is a tanuki, and a servant to Miroku. Miroku often calls him Hachi as a nickname. Hachimon is very loyal to Miroku and saved his life when he was attacked by Mushin. Like Myōga, Hachi acts very cowardly.

Hachi appears very infrequently in the series. His main role is to use his powers of shapeshifting using a leaf to turn himself into a yellow blimp like object to provide air transportation for Inuyasha's group or a monster-like boulder to scare people on Miroku's instructions. He can also shapeshift to look like Miroku, as he has done in episode 93 and he has also shapeshifted into Kagome with Shippo in episode 135. He is voiced by Toshihiko Nakajima in the original television series, Terry Klassen in the English dubbed version, and by Csuha Lajos in the Hungarian dub of the series.

Hachiemon is named after the Japanese kami of war, Hachiman. His nickname Hachi means "bee".