The Heian Period of Japanese history is a really fascinating period, both culturally and historically to me. I even made a whole side-blog devoted to it (15th anniversary this week!). When you read books like the Diary of Lady Murasaki or the Pillow Book, there are a lot of cultural allusions that are hard to translate into English, or even contemporary Japanese culture, and that includes the role of professional diviners called the Onmyōji (陰陽師).

The Onmyoji were not mere soothsayers, but were trained to read various signs and calculations, and compile calendars for the coming year to determine the movements of the gods, moon, stars, etc. This was then used by the aristocracy to make decisions, where to travel and so on.

Much of these calculations were based on practices imported from China: the Five Elements Theory, Yin-Yang philosophy, geomancy,¹ and so on. When we think of elements: we think of earth, wind, fire and water,² but in Chinese philosophy it was earth, wood, metal, fire and water. In the traditional calendar used today across Asia, these philosophies are still preserved. For example, this year (2026) is the yang-fire-horse: (丙午, hi-no-e-uma in Japanese)

But let’s look at a concrete example.

Onmyoji often calculated inauspicious directions of travel. The idea was that a certain Taoist god named Ten-ichi-ji (天一神) would wander in various cardinal directions. If you traveled in the direction that Ten-ichi-ji was dwelling on that particular day, you would suffer the wrath of that god and be cursed. Therefore, people had to avoid traveling certain directions on certain days. This would lead to convoluted efforts to reach your destination from another direction, a practice called katatagae (方違え). People would travel the night before (before it became inauspicious), or travel in a roundabout direction to get there.

In the Pillow Book, Sei Shonagon discusses the hassles of inauspicious directions:

[154] When Her Majesty [Empress Teishi] was in mourning for the previous Regent, she was required to leave the palace at the time of the Great Purification at the end of the sixth month. However, the Office of the Empress’s Household happened to be in a forbidden direction at the time, so she moved instead to the Aitadokoro [residence], which belonged to the Council of State.

Our first night there was hot and extraordinarily dark, and we spent it feeling cramped and rather anxious as we waited for the dawn.

Another example were abstinence days. Onmyoji calculated days that were highly inauspicious, called monoimi (物忌み), which required people to undergo a day of abstinence. People who were stuck at home on an abstinence days had to avoid anything impure: sex, travel, talking too loud, important work, certain foods, etc. They even had to wear special talisman in their hair or hat.

In the Pillow Book, Sei Shonagon recalls an incident with her lover Yukinari:³

[129] One evening, Secretary Controller Yukinari visited the Office of the Empress’s Household, and stayed talking far into the night. He finally left as dawn was approaching, remarking that he must return by the Hour of the Ox since he was obliged to stay at the palace all day owing to an Imperial abstinence.

Translation by Meredith McKinney

By the way, the passage above also contains Sei Shonagon’s famous poem which was later used in the Hyakunin Isshu (poem 62).

Further, she remarks how annoying abstinence days were:

[22] …. You’ve taken special care to send off a beautiful, carefully written letter, and you’re eagerly awaiting the reply — time passes, it seems awfully long in coming, and then finally your own elegantly folded or knotted letter is brought back, now horribly soiled and crumpled and with no signs reminaing of the brush stroke that sealed it. “There was no one in”, you’re told, or “They couldn’t accept it on account of an abstinence”. This is dreadfully dispiriting.

Onmyoji didn’t just make calendars, they also performed various purification rituals, and exorcisms that Buddhist or Shinto priests would not do. In the Diary of Lady Murasaki, the eponymous author⁴ writes about the commotion and rituals the Onmyoji would use to protect Empress Shoshi WHILE SHE WAS IN LABOR:

At the moment of birth what awful wails of anguish came from the evil spirits! Preceptor Shin’yo had been assigned to Gen no Kurõdo, a priest called Myoso to Hye no Kurõdo, and the Master of Discipline from the Hojüji to Ukon no Kurodo. Miya no Naishi’s enclosure was being overseen by Preceptor Chisan; he was thrown to the ground by the spirits and was in such distress that Preceptor Nengaku had to come to his aid with loud spells. Not that his powers were on the wane, it was just that the evil proved so very persistent. The priest Eiko, brought in to help Lady Saisho’s exorcist, became hoarse from shouting spells all night.

This mixture of Buddhist monks (trained in esoteric Buddhism) pairing with exorcists and mediums (Onmyoji) loud in yelling and chanting during a woman’s birth feels weird by today’s standards, but Shoshi’s father, the regent Fujiwara no Michinaga had everything riding on his daughter safely giving birth to a male who could inherit the Imperial Throne, so he spared no expense. Lucky for him, it worked.

Onmyoji gradually lost influence during later centuries of Japanese history, but never quite faded altogether. Technically, they were banned in the early-modern Meiji Period, but gradually reformed as a particular sect of Shinto to this day.

Next time, we’ll talk about a certain legendary Onmyoji named Abe no Seimei (shown above), who is a popular subject of Japanese movies, anime, manga, etc.

¹ Geomancy (lit. “earth divination”) in Chinese culture today can be seen in practices like Feng Shui, the Ba Gua and so on. My wife is Japanese, not Chinese, but she does take an active interest in Feng Shui (called fūsui in Japanese). I am more ambivalent, but in spite of my “logical mind”, I am curious.

² Or just Earth, Wind and Fire. 😁

³ See poem 62 of the Hyakunin Isshu.

4 See poem 57 of the Hyakunin Isshu.