The Tensho period in relation to the world history occurred during the Age of Discovery. Peoples' understanding of the world changed dramatically. Christian daimyo, feudal lords in Kyushu (the western part of Japan) sent an envoy of four boys to then Pope Gregorius ?? . The envoys were the first in the history dispatched to Europe from Japan . It took eight years full of difficulties and glorious adventures before they reached the soil of Europe .

In the mean time, Sakai was in the midst of prosperity as a port setting the new trend of the time. Sakai had once been a liberal city state, but at that time was held under the control of Nobunaga Oda and Hideyoshi Toyotomi. One of local magnates Yoshiro Totoya who had been known as a tea ceremony expert Soeki Sen, was granted the title name of “Rikyu�Eby Emperor. As Rikyu, he became a man of great renown throughout the nation. He also won the respect of Hideyoshi who held the reign of absolute power. But Rikyu's great reknown as a tea expert offended Hideyoshi who vented his anger by ordering Rikyu to commit hara-kiri. This occurred in February and Tensho period ended in that year, the nineteenth year of Tensho.

The Tensho period is later called Azuchi-Momoyama. Koh, one of major cultural objects which blossomed in the time of Azuchi-Momoyama, often shows its significance during the time.

After unifying the Japanese nation in 1573, Nobunaga Oda followed the action of his predecessor Yoshimasa Ashikaga, the eighth shogun of Muromachi era. He ordered the door of Shosoin, the national treasure house in Nara , opened and he cut off a piece of legendary “Ranjatai�E the peerless treasure. The Ranjatai wood is still stored at Shosoin today as one of Japan 's national treasures. On it are stickers indicating the sections cut-off by Yoshimitu and Nobunaga.

Nobunaga must have burned smaller bits of the cut-off piece and admired the elegant fragrance. He regarded this piece of Ranjatai as the ultimate reward recognizing his own distinguished service. In this way, he valued Kohboku and set the unwritten rule, “A piece of Kohboku was heavier than the weight of domain and castle�E

Since then, Koh has developed in line with the development of tea ceremony. People who performed Koh in Tensho period often were well versed in tea ceremony, and vice versa. Koh-ju was a name for professionals of Koh tool who served at Court during the Tensho period. Mataemon Yasuda is the first Koh-ju. He is a grandchild of twelfth-generation descendant of Yoshisada Yasuda, a relative of the Genji Family. Later during the Edo period, Koh-ju created a number of fine Koh ingredients particularly those by Juemon Takai, the eight-generation of Koh-ju who is another distinguished figure in the history of Koh. Since then, the name of Juemon has been succeeded from generation to the next. This is another fact of Koh which has its origin in the Tensho.

* Current successor of “Koh-ju�Eis Nippon Kodo, Inc., which has come to be the unequaled expert in the history of Koh.