This study describes the right upper postcanine teeth of a single individual of a Pleistocene rhinocerotid (Mammalia, Perissodactyla) from the lower to lower Middle Pleistocene Kamo Formation of the Kokubu Group in Aira City, Kagoshima Prefecture, southwestern Japan. These teeth are heavily worn and are identified as P2–M2 with missing M1. They are identified as an indeterminate genus and species of the Rhinocerotidae, although they were previously identified as Rhinoceros aff. sinensis. These dental fossil specimens and the rhinocerotid footprints from the lower to lower Middle Pleistocene of Japan indicate that rhinocerotids certainly existed in Japan during the early to early Middle Pleistocene.