A hand mirror is one form of Japanese-produced mirrors that were commonly used during the Edo period and consistto dateound mirror with a long handle. Keyhole-shaped tumuli that have a similar shape are known as "hand mirror-type keyhole-shaped tumuli. Opinion is divided as to who invented the name of keyhole-shaped tumulus with some attributing the naming to Kunpei Gamo, Norinaga Motoori, or other scholars; however, the actual author is not clear. Currently, major types of tumuli include "keyhole-shaped tumuli," "keyhole-shaped tumuli with a quadrangular rear mound," "long rectangular tumuli with a circular mound at the center," "gourd-shaped tumuli," "circular mounds," "square tumuli," "square tumuli with a circular mound on the top," and "octagonal tumuli," though in fact the shapes of tumuli vary between periods and regions. The "hand mirror-type tumuli" (or hand-mirror shaped tumuli) too, are an example of such variety and are one type of keyhole-shaped tumuli. The huge keyhole-shaped tumulus that is believed to have been built for the first time in Japan is the Hashihaka Tumulus in Sakurai City in Nara Prefecture. The Hashihaka Tumulus and other huge keyhole-shaped tumuli built in Yamato (the current Nara Prefecture) during the second half of the 3rd century, which are considered to be royal tombs, underwent subtle changes in shape over time. The Saitobaru Burial Mounds include keyhole-shaped tumuli that have the same standards as such royal tombs. This suggests that there was close communication between Yamato and the province of Hyuga. In Yamato, however, there are few hand mirror-type keyhole-shaped tumuli. Local chiefs of the province of Hyuga, who had introduced standards for the construction of keyhole-shaped tumuli from Yamato, had abandoned these standards by around the middle of the 4th century and thereafter started to design the unique hand mirror-type keyhole-shaped tumuli. Giant keyhole-shaped tumuli in Yamato (Nara Prefecture) suggest that the central government of the region had acquired great power. It is inferred that Yamato led the design of keyhole-shaped tumuli, which symbolized the funeral service common to each region of the country. At some point in time, however, Yamato's leadership may have broken off or slackened. During the interval, local chiefs in southern Kyushu started to design keyhole-shaped tumuli that were unique to the region. In all probability, internal conflicts within the bureaucracy underpin this gap of leadership in the land of Yamato. During this period, the area for royal tombs in Yamato moved from the foot of Mt. Miwa in central Nara Prefecture to the Saki Hills in the northern part of the prefecture. text: Toshiyasu Kuroda (Toppan) supervised: Kazuo Yanagisawa (Miyazaki Univ.)