The Universe Within a Small Bowl - The Mystery of Yohen Tenmoku Tea Bowl

Countless stars twinkling in pitch-black darkness, a fantastical world woven with blue luminescent radiance—this is the Yohen Tenmoku tea bowl. Created in China during the Southern Song Dynasty (12th-13th century), this tea bowl is called "the universe within a bowl," with only three existing in the entire world. All three are in Japan, and each is designated as a National Treasure, making them true treasures of humanity.

The Yohen Tenmoku tea bowl housed at the Seikado Bunko Art Museum is affectionately known as "Inaba Tenmoku" and is considered the masterpiece among the three, displaying the most vivid iridescence. Its mystical brilliance, which changes into seven colors depending on the viewing angle, continues to captivate viewers even after 800 years.

What is Yohen Tenmoku - A Miraculous Beauty Born of Chance

Yohen Tenmoku is a type of black-glazed tea bowl fired at the Jian kilns in Fujian Province, China. The term "Yohen" originally meant "kiln transformation" (accidental changes in the kiln), and later the character "Yo" (meaning star or shine) was applied due to its star-like brilliance.

During the Song Dynasty in China, white tea was popular, and black-glazed bowls that enhanced its color were highly prized. It is said that the Jian kilns fired as many as 100,000 tea bowls at once, but Yohen Tenmoku was born by chance from among them. The spots of various sizes floating on the black glaze surface and the blue and rainbow-colored iridescence appearing around them remain a mysterious phenomenon not fully understood even with modern scientific technology.

Transmission to Japan and the History of Inaba Tenmoku

This precious tea bowl was transmitted to Japan during the Kamakura period and was positioned as the highest grade tea utensil in the tea ceremony culture of the Muromachi period. In the Muromachi period document "Kundaikan Sochoki," it received the highest evaluation: "There is nothing greater in this world."

The Yohen Tenmoku at Seikado Bunko Art Museum was originally owned by the Tokugawa shogunate. It was bestowed by the third shogun Tokugawa Iemitsu to Lady Kasuga (wife of Inaba Masanari), and later passed down to the Inaba family, lords of Yodo Domain, hence the name "Inaba Tenmoku." In 1934, it became the property of Iwasaki Koyata, the fourth president of Mitsubishi, and is now carefully preserved at the Seikado Bunko Art Museum.

Why It's a National Treasure - Its Value in Japanese Culture

The reason Yohen Tenmoku was designated as a National Treasure lies in its rarity, artistic value, and importance in Japanese culture. All three complete Yohen Tenmoku bowls existing in the world have been carefully preserved in Japan. This is testament to Japanese aesthetics and the spirit of protecting and passing down precious cultural properties.

Iwasaki Koyata stated, "One should not use the nation's treasures for personal use," and never used it personally even once. This spirit embodies the Japanese philosophy of cultural property protection, treating cultural assets as public treasures to be passed down to future generations.

Highlights - A Feast of Ever-Changing Light

The greatest charm of Yohen Tenmoku is its ever-changing beauty. The spots scattered throughout the interior of the bowl are like stars shining in the night sky. Around each spot, iridescence in blue, purple, green, and yellow shines like a rainbow. Depending on the angle of light and viewing position, its expression changes moment by moment, providing a mystical experience as if holding the "universe" in one's hands.

At the Seikado Bunko Art Museum, this National Treasure is displayed in a special exhibition case for optimal viewing. The 360-degree viewing display method allows visitors to appreciate not only the interior but also the exterior beauty of the tea bowl.

Seikado Bunko Art Museum - A Temple of Culture in Marunouchi

In October 2022, the Seikado Bunko Art Museum relocated to the first floor of the Meiji Seimei Building in Marunouchi, Tokyo, starting anew as "Seikado@Marunouchi." Within the majestic architectural beauty of the Meiji Seimei Building, designated as an Important Cultural Property, visitors can appreciate approximately 6,500 pieces of Eastern ancient art, including the National Treasure Yohen Tenmoku.

The museum is ideally located just a 5-minute walk from Tokyo Station and directly connected to Nijubashimae Station on the Chiyoda Line. The area is surrounded by many cultural facilities and tourist spots, including the Imperial Palace, Tokyo International Forum, and Mitsubishi Ichigokan Museum, making it an ideal base for Tokyo sightseeing.

The Mystery of Yohen Tenmoku Living in Modern Times

The production technique of Yohen Tenmoku has long been a mystery, with many ceramicists challenging its reproduction. In recent years, Kyoto ceramicist Yoshiaki Dobuchi and Aichi's Sōkichi Nagae have succeeded in reproduction using unique techniques, but it still largely depends on chance and complete control remains difficult.

Recent scientific research has proposed theories about the nature of the iridescence, including thin-film interference and multiple interference theories, but how this beauty was created with technology from 800 years ago remains unsolved. This mystery is also part of Yohen Tenmoku's appeal.

Worth Visiting - A Once-in-a-Lifetime Experience

The Yohen Tenmoku tea bowl is more than just an art object. It is a symbol embodying Japanese aesthetics, tea ceremony culture, and the spirit of cultural property protection, as well as evidence of the pinnacle of human creativity. Visiting the Seikado Bunko Art Museum and encountering this miraculous tea bowl will be a precious opportunity to touch the depths of Japanese culture.