Matsuo Sogo (1847-1888) was the seventh headmaster of the Matsuo school. His sai is Koukosai. He served the Owari domain as an official since the 2nd Wan Kosai. He was the 7th Kikosai, who moved to Nagoya after his house in Oshikoji, Higashinotoin, Kyoto was destroyed by fire in the Battle of Toba-Fushimi at the end of the Edo period.
