The Mystery of the Lunar Eclipse: Japan’s Celestial Folklore
When the moon turns a deep, rusty red and fades into the shadow of the Earth, modern observers look up in awe. Cameras click, and social media lights up with images of the “Blood Moon.” However, in the Japan of antiquity, this celestial phenomenon was not a moment of beauty; it was a moment of dread. Known as Gesshoku (月食), or “bitten moon,” the lunar eclipse has a deep, mysterious history in Japanese culture, transforming from a terrifying omen to a celebrated event.
Ancient Origins: The Fear of the Unseen
To understand the “Mystery of the Lunar Eclipse” (Gesshoku no Kai), one must travel back to the Heian Period (794–1185). During this era, life in the imperial court was governed by Onmyodo, a traditional Japanese esoteric cosmology based on Chinese philosophies of Yin and Yang.
In this worldview, the celestial bodies were directly linked to the fate of the emperor and the state. The sun represented the Emperor (descendant of the Sun Goddess Amaterasu), while the moon was often associated with the Empress or the natural balance of water and tides. An eclipse was seen as a disruption of the cosmic order—a temporary defeat of light by darkness.
Aristocrats viewed the eclipse as a manifestation of Kegare (spiritual pollution or withering of spirit). It was believed that looking directly at the moon during an eclipse could invite misfortune, illness, or even death.
The Legend of the Poisoned Sky
While Western or Indian mythology often depicts a dragon or demon swallowing the moon, Japanese folklore took a more pragmatic, yet equally terrifying, approach to the phenomenon.
The prevailing superstition was that during a lunar eclipse, the moon became “sick.” As the shadow consumed the lunar surface, it was believed that a toxic miasma or poison would drip from the sky. This led to a very specific and widespread custom: covering the wells.
The Well-Covering Custom
Villagers and townsfolk would rush to place wooden lids or woven mats over their water wells the moment the eclipse began. The fear was that the “poison from the moon” would fall into the water supply, rendering it undrinkable and spreading plague throughout the community.
The God Tsukuyomi
In Shinto mythology, the moon is personified by Tsukuyomi-no-Mikoto. Unlike his radiant sister Amaterasu, Tsukuyomi is an enigmatic figure. Legends state that he killed the goddess of food, Uke Mochi, out of disgust, causing him to be estranged from the sun. An eclipse was sometimes interpreted as Tsukuyomi hiding his face in shame or anger, withdrawing his protective light from the archipelago, leaving the land vulnerable to Yokai (spirits) and dark forces.
Modern Culture: From Omen to Attraction
Today, the fear of Gesshoku has largely vanished, replaced by a fascination with astronomy. Japan is now one of the premier destinations for “astro-tourism.”
The “Blood Moon” is no longer a sign of impending doom but a motif popular in Anime and Manga (such as Demon Slayer or Naruto), where it often signals a time when magic is heightened or boundaries between worlds blur. This pop-culture usage pays homage to the ancient belief in the eclipse’s supernatural power without the associated existential dread.
Furthermore, the tradition of Tsukimi (Moon Viewing), usually held in autumn to honor the harvest moon, has expanded. When an eclipse is forecast, observatories in Tokyo (like the Roppongi Hills Sky Deck) and planetariums across the country sell out tickets instantly. It has become a romantic and communal event rather than a night of isolation.
Traveler’s Tips: experiencing the Moon in Japan
If you are planning a trip to Japan and want to experience the celestial culture, here are a few tips:
- Best Viewing Spots: For a mix of culture and astronomy, head to Nara Park or the rooftops of Kyoto. Seeing an eclipse (or a full moon) hovering over the silhouette of a five-story pagoda offers a hauntingly beautiful connection to the past.
- Tokyo Skytree: For a modern twist, the Tokyo Skytree often hosts special viewing events. Being 634 meters in the air puts you above the city lights for a clearer view.
- Goshuin Collecting: Many Shinto shrines issue special Goshuin (stamped seals) on days of significant astronomical events. Visit shrines dedicated to Tsukuyomi, such as the Tsukuyomi Shrine in Kyoto or Ise, to collect these rare mementos.
- Seasonal Timing: While eclipses follow their own schedule, visiting during September or October aligns with traditional Tsukimi festivals, where you can eat rabbit-shaped rice dumplings and enjoy the moon even if it isn’t eclipsed.
Sources & Further Reading
For those interested in diving deeper into the mythology and history of Japanese astronomy, the following texts are essential:
- The Nihon Shoki (Chronicles of Japan): Contains the founding myths of Shinto gods, including Tsukuyomi, and early records of astronomical events.
- The Tale of Genji (Genji Monogatari): Written by Murasaki Shikibu, this classic text offers insight into Heian-era superstitions regarding celestial bad omens.
- The Kojiki (Records of Ancient Matters): The oldest extant chronicle in Japan, detailing the birth of the deities.