I just realized I ever made this simple explanation of the Heian period, Onmyoudo, and the modern adaptation of that stuff. I made this last year and ever posted it on Twitter. I took Japanese literature during my college time but was not really good at this kind of stuff (I was more focused on literature rather than the culture), but I would like to share what I know. Let me know if there is any mistake you found here and don’t be scared to correct me if I’m wrong. Thank you.
Starting in the 6th century, in East Asia, things also happened there and one of them was the influence of faith and religion. Confucianism from China and Buddhism from India started influencing Japanese society during that time. Back then, the government of Japan was ruled by aristocrats. No longer after that, during the 7th century, a lot of scholars and monks were sent to China to study. At the same time during the end of the 7th century, Japan began to know the terms Tennou (天王) and Nihon (日本).
The highlight of this explanation is the Nara and Heian periods.
Nara period (710-784) was the era where everything was still heavily influenced by the Chinese. The capital during that time was located in Nara and the capital was modeled on the Chinese T’ang dynasty. The Chinese language was intensively studied, in most of the government documents were using Chinese. During that time, some characters were also adapted to Japanese. Japan also copied Chinese manuscripts (especially about Buddhism).
The grand results during this era were Japan’s well-known storybooks: Kojiki (古事記) and Nihon Shoki (日本書紀). Manyoushuu (万葉集), the famous Japanese native poetry anthology was also written during this era.
Moving on to Heian, this is the special era that became the title of this simple explanation.
The Heian period (794-1185) was the era when Japan started to become its real self. The Heian period started when the capital was moved from Nara to Kyoto. Even though the Imperial House seemingly hold power on the surface, behind them, the Fujiwara clan is controlling the government. Japanese culture was also born during this era (building, clothing, paintings). Japan also started to establish its own characters in its language (kanji, hiragana, and katakana).
The famous literary work that was born during this era was The Tale of Genji (源氏物語) by Murasaki Shikibu. It is also said that this work was the oldest novel in the world. Another work that is worth knowing is Konjaku Monogatari (今昔物語), the collected stories of folklore and Buddhism related stories. A lot of them are about the encounter between human and spiritual beings. For example, tales of encounters with Hyakki Yakou ( 百鬼夜行 ) or Night of Hundred Demons, tengu, or various other obake.
Back to the history books that were mentioned before, I’d like to talk a little bit about it. The first is the Kojiki. It is also said as the “Record of Ancient Matters”. Kojiki is considered the sacred text of the Shinto religion. It consists of myths, legends, and historical accounts from the earliest days of creation up to the reign of Empress Suiko (628). It became the source for ceremonies, customs, divination, and magical practices of ancient Japan.
Next, Nihon Shoki (日本書紀). It is also known as Nihon gi. This work is considered the “official history of Japan”. It consists of 30 chapters that conclude with myths, and legends of ancient Japan, and is also an important source of Shinto. The late chapters that start from the 5th century and so on talk about several powerful clans as well as imperial families.
Another stuff that I want to talk about here is Onmyoudo (陰陽道).
Onmyoudo is the Japanese traditional esoteric cosmology, a mixture of natural science and occultism. It is also called “the way of yin and yang”. It was influenced by Taoism, Confucianism, and Buddhism. At first, this Onmyoudo wasn’t considered a religion, but in the 5th-6th century and also late 7th century, it finally became an independent faith. In the 9th century, Onmyoudou interacted with Shinto and Goryou and then developed a new unique system in Japan. It is also becoming the latest hit in the Heian period because during this era everyone believes that most phenomena are caused by spiritual-related things. The activities in Onmyoudou include astronomy, calendar-making, the reckoning of time, divination, observing nature, and fortune-telling. During the Heian period, the activities that were held were a little bit more religious services such as warding off evil for preventing natural disasters and epidemics (and for the productiveness of grain), as well as curses against opponents.
Then, we have Onmyouji, the person who does Onmyoudou professionally. You can say they are the practitioner of Onmyoudou. Back then, Onmyouji was an actual official position in the Bureau of Onmyou. They were recognized by society and the government as legal jobs. People at that time also believed that they could summon and control shikigami. Some of the notable onmyouji was Kamo no Yasunori, Abe no Seimei, Ashiya Douman, Kamo no Tadayuki, and Haruo Tsuchimikado.
From what I know, here are the simple differences between Onmyouji and Jujutsushi. They are somewhat similar to each other and I think they only have slight differences, not that much.
Nowadays, we can still see some of the modern adaptations of literary works actually adapting the stories about stuff I explained before. Here I made a list of the modern adaptation (anime) that used the stories related to Onmyouji or Jujutsushi. Personally, I really like Jujutsu Kaisen. There is actually a continuation of this presentation but I think I’m not going to talk about it now. That’s it. That’s all I know. Hopefully, it could be a simple guide for you guys who is interested in Onmyouji-related stuff or just as extra knowledge. Thank you for reading!