Yōhen Tenmoku and Ryōkō-in

Yōhen tenmoku, fired at the Jian kilns of the Southern Song

Tenmoku are the most formal of the bowls used for drinking matcha, and are characterized by a funnel-like shape and black glaze. The black-glazed bowls fired at the Jian kilns in Fujian Province during China's Southern Song dynasty (12th–13th centuries) are called kensan (建盞, Jian ware), and among the vast numbers of kensan produced, those on which beautiful iridescence happened to appear in the kiln are yōhen tenmoku. The word yōhen (曜変) is said to have originally been 窯変 (yōhen, "kiln transformation"), with the character 曜, meaning brilliance, substituted; in Muromachi-period Japan these bowls were ranked as the very finest of tea bowls.

Only three intact yōhen tenmoku exist in the world, all of them in Japan and all National Treasures: the "Inaba Tenmoku" of the Seikadō Bunko Art Museum in Tokyo, the bowl of the Fujita Museum in Osaka, and the bowl of Ryōkō-in in Kyoto. The three are also praised as the "three peerless yōhen" (yōhen-chū no sanzetsu).

How the three differ

Ryōkō-in's bowl has at its rim the nejikaeshi (a slightly inturned lip) characteristic of kensan and a low, small foot, and its jet-black glaze is applied thickly, with yōhen appearing over almost the entire inside. Its star-like spots are small and its blue light thin and short, so although it lacks the brilliance of the Inaba Tenmoku, it has deep character and dignity.

The Inaba Tenmoku has spots inside that shine blue and yellow, and it bears this name because from the Edo period onward it was handed down in the Inaba family, lords of the Yodo domain. The Fujita Museum's bowl is the only one of the three with beautiful yōhen both inside and outside.

The Important Cultural Property "yōhen tenmoku tea bowl" and fragments

A tea bowl designated as a national Important Cultural Property under the name "Yōhen Tenmoku Tea Bowl" is at the MIHO MUSEUM in Kōka City, Shiga Prefecture. Handed down in the Maeda family of Kaga, it has spots called yuteki ("oil spots") floating inside and out, and part of its inside shows yōhen. Fragments of yōhen tenmoku have also been found in China, near the site of the Southern Song palace in Hangzhou, Zhejiang Province.

All three National Treasures on view in spring 2019

Because Ryōkō-in does not accept general visitors, its treasures, including the yōhen tenmoku, had rarely been seen. In spring 2019, the MIHO MUSEUM in Kōka City, Shiga Prefecture, held a special exhibition bringing together Ryōkō-in's treasures, "Daitokuji Ryōkōin: National Treasure Yōhen Tenmoku and Hasōai" (破草鞋, "worn-out straw sandals") (March 21–May 19), and the yōhen tenmoku was shown.

At the same time, National Treasure yōhen tenmoku were also on display at the Seikadō Bunko Art Museum in Tokyo (April 13–June 2) and in the Fujita Museum exhibition at the Nara National Museum (April 13–June 9), making it possible to see all three National Treasures in the same spring.

Ryōkō-in, founded by Kuroda Nagamasa

Ryōkō-in is one of the subtemples (tatchū) of Daitoku-ji, a head temple of the Daitoku-ji branch of the Rinzai school, and stands on the southwest side of the main temple. It was founded in 1606 (Keichō 11) by Kuroda Nagamasa to pray for the repose of his father, Yoshitaka (Josui), with Shun'oku Sōen (春屋宗園) as its founding patriarch and Kōgetsu Sōgan (江月宗玩) invited as its first abbot. Kōgetsu was the second son of Tsuda Sōgyū of the Tennōjiya, a wealthy Sakai merchant and tea master, and many of the famous treasures handed down in the Tennōjiya are still at Ryōkō-in. The grounds also contain the Kuroda family mausoleum (tamaya), an Important Cultural Property thought to have been completed in 1608.

The National Treasure shoin is a building roofed with kokera (thin wooden shingles), formed when a large room and a wide veranda were added around 1649 (Keian 2) around the Mittan-seki (密庵席), a tea room of four and a half mats plus a daime (three-quarter) mat built as a separate structure in the Kan'ei era (1624–43). It became a National Treasure on April 27, 1961. The Mittan-seki is a somewhat shoin-style tea room said to reflect the taste of Kobori Enshū (小堀遠州). It has two tokonoma alcoves, intended for hanging the calligraphy of the Southern Song Zen monk Mi'an Xianjie (密庵咸傑, Mittan Kanketsu in Japanese; the calligraphy is a National Treasure) and a letter by Sen no Rikyū. It is a representative tea room of the early Edo period.

Daitoku-ji's other National Treasures and the number of craft National Treasures

Besides the Ryōkō-in Shoin, Daitoku-ji's National Treasure buildings are the Hōjō and Genkan of the main temple (1635–36), the Karamon, and the Hondō of its subtemple Daisen-in (1513), so 4 of Kita Ward's 5 National Treasure buildings are concentrated at Daitoku-ji. The gardens of the Hōjō and of the Daisen-in Shoin are Special Places of Scenic Beauty, and among paintings, works such as Kannon, Monkeys, and Cranes by Muqi (牧谿, Mokkei) are also National Treasures.

In Kyoto City's tally dated April 1, 2026, 13 of the 217 National Treasures in the city are crafts (254 nationwide), and Ryōkō-in's yōhen tenmoku is one of them.

Daitoku-ji's buildings from outside and yōhen tenmoku at exhibitions

You can freely enter the grounds of Daitoku-ji (Murasakino Daitokuji-chō, Kita Ward) and view from outside the temple complex, where the Chokushimon, Sanmon, Butsuden (Buddha hall), and Hattō (Dharma hall) line up from south to north.

• Getting there: Take a city bus to "Daitokuji-mae." Ryōkō-in is on the southwest side of the main temple.
• The main temple (Hōjō and Karamon) is normally closed. The subtemple Daisen-in is open year-round, 9:00–16:30; 500 yen for adults, 300 yen for elementary and junior high school students (as of October 2026).
• Seeing a real yōhen tenmoku: chances to see Ryōkō-in's bowl are almost entirely limited to exhibitions. In 2026 it is shown at the Heiseikan of the Tokyo National Museum in a special exhibition marking the 700th anniversary of Daitoku-ji's founding (October 14 – December 6), during the first term only, until November 8. During the first term the museum is closed on Mondays but open on Monday, November 2. The bowls of the Seikadō Bunko Art Museum (Marunouchi, Tokyo) and the Fujita Museum (Miyakojima-ku, Osaka) are sometimes shown in their own museums' exhibitions.