Firstly, yokai can be described as a product of the imagination born from people’s fear, awe, and anxiety toward nature and unknown presences that writhe within the darkness. For this reason, the yokai have taken on strangely grotesque and uncanny appearances, becoming a subject of people’s fear. Information regarding these various yokai soon came to be widely shared among the people, and the common recognition of their respective features and names led to the creation of a fixed image for each individual yokai. Then, there was a shift to a new stage as their images were further captured through visual renditions. The yokai that were depicted proved to have a great impact by unveiling their appearance directly before people’s eyes. They widely and profoundly penetrated the hearts of many, laying the foundation for their explosive dissemination in times to come.
What played a major role in visualizing these yokai were picture scrolls. The history of picture scrolls in Japan dates back to ancient times, with some of the earliest examples produced since the Nara period (710–794 CE). All of the works depicting the yokai that can be confirmed at present are from the Kamakura period (1185–1333 CE), and the majority of existing works were produced during the Edo period (1615–1868 CE). The themes, however, are diverse, and it can indeed be seen that yokai picture scrolls developed significantly during the Edo period. In addition, there are some notable events that can be confirmed in the process by which these picture scrolls developed. One is that the position of the yokai changed from a supporting role to the central protagonist role. For example, there are the famous Shuten-dōji Emaki and Tsuchigumo-sōshi Emaki that for long continued to be depicted since before the Edo period. Both tell the story of Minamoto no Yorimitsu (948–1021 CE), a brave samurai of the Heian period (794–1185 CE), and his four lieutenants on their quest to exterminate the Oni (“demon”) and Tsuchigumo (“earth spider”). The central subject of these scrolls is Yoshimitsu’s heroic tale, with the Oni and Tsuchigumo appearing as supporting characters defeated by Yorimitsu. Meanwhile, the Tsukumogami Emaki, which depicts yokai in the form of objects, was created for the purpose of illustrating the virtues of Buddhist teachings. The scroll tells the tale of various everyday tools, such as old desks and kitchen utensils, that were discarded while a house that had come to be occupied by spirits was cleaned. While holding a grudge against human beings and repeatedly engaging in evil deeds, such spirited objects eventually devoted themselves to the teachings of Buddhism and attained Buddhahood. In this way, the scroll aimed to communicate the blessed teachings of Buddhism that enabled even inanimate objects to rest their spirits. In other words, the objects depicted here are merely tools used to convey the magnificence of Buddhism.
The Hyakki Yagyō Emaki are a pioneering example of a work in which yokai, which until then had only served in a supporting role, came to be depicted as a central subject. The oldest surviving scroll is said to have been painted by Tosa Mitsunobu (1434?–1525 CE) during the Muromachi period (1336–1573 CE) and has been handed down to the Shinjuan sub-temple located at the site of the Daitoku-ji Temple in Kyoto. Unlike the three picture scrolls introduced earlier, a distinct feature of this scroll is that not only are humans not depicted at all but even mere hints of their presence cannot be felt. What is indeed presented here is a world that features only yokai. This picture scroll was a subject that continued to be painted by artists of the two mainstream schools of modern painting: the Tosa school and the Kanō school. Many examples of the most popular type were depicted in the Edo period, and yet there are also several other types of work that are referred to as the Hyakki Yagyō Emaki, thus illustrating the sheer expansion and popularity of its theme and motif.
Meanwhile, various types of yokai picture scrolls other than the Hyakki Yagyō Emaki were depicted during the Edo period, giving rise to a vibrant and diverse multitude of works. Furthermore, the times saw a particular event that led to the dramatic development of yokai culture. With the development of woodblock printing, multicolored nishiki-e (“brocade pictures”) became available to all people at an affordable price, resulting in yokai permeating the lives of the masses. Therefore, people’s view toward the yokai as scary and awe inspiring changed, bringing about the emergence of an admirable and friendly kind of yokai. Another change was that the yokai came to be depicted not only on paper media, such as nishiki-e and picture scrolls, but also in the form of three-dimensional objects. This new view toward yokai that emerged during the Edo period has been inherited to the present day, leading to the formation of today’s yokai culture, which is dominated by cherished and almost character-like renditions of yokai. In order to gain a comprehensive and contextual view of this situation, it is perhaps important to go back in time to look at various materials related to yokai.