Sekiyama Moritoshi
Sekiyama Moritoshi (Kanji: 関山盛利) was a Japanese 4 dan professional (d. Aug 1939).
He became the patriarch of Japan’s first five-generation professional Go family.
Sekiyama Moritoshi’s son Sekiyama Riichi 9p was the first modern Honinbo. His grandson Sekiyama Toshio and great-grandson Sekiyama Toshimichi were also 9p. His 2nd-great-granddaughter Sekiyama Honoka is 1p, thus the fifth generation of professional Go players.
He was affiliated with the Nihon Ki'in, Kansai branch. After the Kansai Ki'in became independent, his son, grandson, and great-grandson were affiliated with it. But his 2nd-great-granddaughter is affiliated with the Nihon Ki'in.