動物信仰から見る古代日本の変動Ancient Japan's Shifts Through Animal Worship

Ancient Japan’s Animal Worship Reveals Jomon and Yayoi Beliefs

Why Deer Replaced Boars in Yayoi Ritual Symbolism

Ancient Japan remains shrouded in mystery. While archaeology, folklore, cultural anthropology, and genetics have accumulated remarkable achievements, a complete understanding remains elusive. Particularly in Japan’s prehistoric eras—namely, the Jomon, Yayoi, and Kofun periods—there was no written culture, leaving their true nature difficult to ascertain clearly, causing persistent confusion to this day. Nevertheless, integrating various scholarly findings does allow for fascinating insights into ancient Japanese history.

For example, previous research generally assumed that the Jomon people were a single cohesive group, but recent studies have gradually revealed that they were, in fact, a layering of people with diverse origins. Furthermore, it is becoming increasingly clear that the archipelago’s primary ancestry involves three significant currents: the indigenous Jomon people, the Yayoi people originating from Northeast Asia, and the Kofun people from East Asia. Since the Kofun people introduced wet-rice cultivation techniques, historical periodization is rapidly being reconsidered. Interestingly, many of these new findings align with the worldview expressed in ancient mythology and traditions, notably in the Kojiki (compiled in 712). These myths might represent fragments of real historical events transformed through different ideological perspectives. My own extensive independent research has led me to firmly regard the mythology recorded in the Kojiki as foundational. Therefore, this article examines the religious differences between the Jomon and Yayoi people by exploring the sacred animals they worshipped.

Those who have traveled to Nara have likely seen the numerous deer living around Nara Park. Deer have historically been considered divine messengers (神の使い), throughout Japan, especially in Nara, home to the Kasuga Taisha Shrine. Because of this belief, deer roam freely in Nara—and also at Hiroshima’s Itsukushima Shrine—in a manner reminiscent of sacred cows in India, leading to unchecked deer populations. As a result, deer overpopulation has become problematic nationwide, causing severe damage to farmland and forests. Yet, when speaking to people from Nara, few can explain why deer became objects of worship. When exactly did deer worship begin?

The answer lies in archaeological discoveries of ancient artifacts. The Jomon people, as their name implies, created vast quantities of pottery, typically decorated with rope-like patterns (“縄文,” jomon), but they very rarely included pictorial art. Animals, instead, were predominantly crafted into clay figurines known as “doseihin” (土製品). Existing research indicates that among these Jomon figurines, wild boars were depicted most frequently, accounting for half of the total animal figurines. Surprisingly, deer representations are almost nonexistent. Deer were certainly present during the Jomon period and, alongside wild boars, were critical as food sources for hunter-gatherers. Although equally important, deer were mysteriously not revered by the Jomon people, unlike boars.

This situation persisted for approximately 10,000 years of the Jomon period, until a drastic shift occurred with the arrival of the Yayoi people from the area near the western Liao River in Northeast Asia, who brought farming practices centered around millet and tubers. With the Yayoi period, the once-prominent boar worship of the Jomon era rapidly declined, and previously nonexistent deer worship flourished dramatically. Interestingly, Yayoi people commonly painted images on their pottery, and their bronze ritual bells known as “dotaku” (銅鐸) often featured scenes depicting ceremonial practices. Remarkably, deer motifs became overwhelmingly common during this period. Moreover, Yayoi pottery typically portrayed deer with antlers, whereas dotaku predominantly depicted antlerless deer. Why this distinction?

The foundational work on this topic was conducted by the archaeologist Hideji Harunari (春成秀爾), a leading Yayoi-period researcher. In 1989, Harunari comprehensively analyzed Yayoi-period imagery, meticulously counting motifs engraved on dotaku. According to his findings, deer appeared 135 times (32.9%), human figures 59 times (15.2%), fish 40 times (10.3%), birds 27 times (6.9%), boars 23 times (5.9%), and buildings merely 2 times (0.5%). When focusing solely on animals, deer accounted for 63.4%, followed by birds at 43.9%, a prevalence linked to female shamans depicted in bird costumes during rituals, symbolizing spiritual guidance when crossing seas from the Korean Peninsula.

Further analyses of Yayoi pottery paintings revealed that deer appeared 88 times (41.1%), buildings 46 times (21.5%), human figures 26 times (12.1%), dragons 14 times (6.5%), birds 13 times (6.1%), and boars only once. These findings were subsequently refined by archaeologist Hiroyuki Hashimoto (橋本裕行) around 1996. Over the following seven years, despite increased archaeological discoveries, the proportion and rank of these motifs remained consistent, solidifying deer as the principal motif in Yayoi pottery art.

This shift from boar to deer symbolism coincides precisely with the beginnings of agriculture in Japan. While Jomon people likely cultivated chestnuts and some grains or hemp, substantial agricultural advancement occurred during the Yayoi era. Yet, the central question remains: why did the advent of agriculture trigger this symbolic shift from boars to deer? The fascinating answer lies in the parallel life cycles between deer and rice cultivation. The Japanese native deer species, known as “nihonjika” (ニホンジカ), enters its mating season precisely when rice grains ripen (October–November). Their birthing season occurs in May, exactly matching rice seedlings’ growth period. Male deer grow branched antlers from around age four; these antlers begin as soft velvet (“rokujou,” 鹿茸) in early summer, mature over summer, and shed by winter, mirroring rice’s seasonal growth cycle (details of this relationship will be addressed separately).

Indeed, deer antlers featured prominently in Yayoi rituals, as documented in the Kojiki myths, clearly indicating their profound ceremonial significance, particularly for predicting agricultural harvests. Yayoi people worshipped deer as earth spirits (“chirei,” 地霊), crucial for agricultural productivity. Archaeological research further indicates reduced deer hunting activities in Western Japan since the Yayoi period. My investigations consistently emphasize northeastern Tohoku to provide comparative insights. Notably, deer worship is scarcely observed in northeastern Tohoku, which favors boar and bear reverence, whereas deer worship remains visible around Kasuga Taisha and Itsukushima Shrine in Western Japan. This contrast likely stems from northeastern Tohoku’s prolonged Jomon lineage and Western Japan’s sustained Yayoi influence.

A similar tradition can be observed even in Okinawa’s Kerama Islands, where the native Kerama deer (ケラマジカ) remain revered. Western Japan, particularly Okinawa, retained Yayoi-influenced deer worship traditions that continued and evolved through the subsequent Kofun period, whereas such changes did not occur in eastern regions such as northeastern Tohoku due to the enduring Jomon influence.

Of course, deer are just one example of numerous intriguing Yayoi customs, including bird and dragon worship imported through China and Korea. This article introduced foundational aspects of boar and deer worship, but future articles will further explore these other beliefs, especially since the Yayoi period is notably characterized by ritual governance led by female shamans.