Tensho is the name of the Imperial Japanese era which lasted from 1573 to 1591 AD. While this was just a few years, many dramatic events happened during the period making it unique and remarkable. The Tensho era followed the Muromachi period and in many ways was a continuation of the achievements of that period. The Muromachi period was established by Takauji Ashikaga in 1336 and lasted under the Shogunate government for two hundred and thirty years. The revolutionary and charismatic samurai leader, Nobunaga Oda exiled the fifteenth and last general of Muromachi Shogunate, Yoshiaki Ashikaga. Thus ended the Muromachi period.. The Muromachi culture that had blossomed and been treasured by high ranking samurai warriors continued. The samurai had earlier borne arms but had turned into sophisticated court nobles. Their civilized culture continued to prosper after Muromachi ended and has been passed down to generation after generation.

  It was such samurai nobles that created the unique stage format of Noh-play. They also enjoyed renga literature, a linked-verse poem making. They sought after philosophical truth in Tea Ceremony and established the art of flower arrangement. The elegance of Koh culture enjoyed by Heian nobles was systematized and established as Koh-do by Sanetaka Sanjonishi, one of the most sophisticated court intellectuals during the Muromachi era. This unique art of Koh is found only in Japan. All these unique cultural artifacts made a step further progress during the Tensho period.

  Koh was brought to eastern Asia with Buddhism. It arrived in Japan as fragrant wood which was burned while praying. Through the course of the one thousand years since its arrival, people developed Koh burning for pleasure, and the original Koh burning for Buddhism prayer took different forms for different purposes such as ShoKoh, MaKoh and SuteKoh. During the Tensh period, the format of today’s Koh incense was developed.