Emperor Tenji

Emperor Tenji (天智天皇, 626–672), known as Prince Naka no Ooe before his accession, was the thirty-eighth emperor and one of Japan's great reforming rulers. Together with Nakatomi no Kamatari, he carried out the Taika Reform (645), dismantling the Soga clan's monopoly on power and reorganizing Japan along Tang Chinese administrative lines. This reform laid the groundwork for Japan's centralized imperial state.

He is enshrined at Omi Jingu (Otsu, Shiga), built near his capital at Otsu on Lake Biwa. As the emperor who introduced Japan's first official water clock (rōkoku), he is also venerated as a patron of time-keeping and poetry—his famous poem about the autumn harvest opens the Hyakunin Isshu anthology.