Honinbo Sansa (本因坊算砂 Hon'inbō Sansa, Nikkai, 1559-1623) was a famous Go player.
Sansa was the first head of the Honinbo house and the first Meijin, taking the name Sansa. Sansa was the rival of Kashio Rigen. He was also a strong shogi player (he was both the first Meijin Go-Dokoro and Meijin Shogi-Dokoro). He was a Buddhist priest of the Nichiren sect and his dharma name was Nikkai. He lived in a temple pavilion called Honinbo from where he taught Go.
"In 1588, Nobunaga's successor, Toyotomi Hideyoshi, organized a large-scale competition to systematize the rankings of Go players. Nikkai, a high-ranking Buddhist monk, who was Nobunaga's Go teacher, won this competition and Hideyoshi decreed that from then on all other players should take black or a larger handicap from him. Nikkai was also awarded a stipend which began the government patronage that enabled Go to flourish in Japan. (Bozulich, 1999)" 
Bozulich, R. (1999). "Go Seigen, the 20th century's greatest player". Yomiuri Shimbun. Retrieved May 30, 2005