Tenchi Meisatsu

In 1661, Yasui Santetsu is a member of the Yasui House of the Four Houses of Go. However, he's beginning to doubt that Go is his true calling. Outside of the Go house, he goes by the name Shibukawa Harumi, and he's fascinated by mathematical and astronomical problems. Specifically, Harumi is pouring all of his energy into creating a new Japanese calender. The story is based on the actual astronomer and calender-reformer Shibukawa Harumi (1639-1715). In Harumi's time, the Japanese used the Chine...