Segawa Yoshio
(b.1913, died 2001-03-22) Nihon Ki-in pro, 8 dan in 1970.
Pupil of the well known Kitani Minoru and Kubomatsu Katsukiyo. His own student was Oka Mitsuo.
The list of professional players' Go styles describes his simply as "thick".
Segawa was a member of the Japanese team for the 1960 Japan-China Goodwill Exchanges, in which he beat Liu Dihuai (of the famous North Liu South Guo duo) 2-1 [1], playing White with no komi.
He was promoted 9 dan in 1981, after his retirement (see http://www.nihonkiin.or.jp/player/htm/ki001005.htm).
[1] The original text from Liu's article says that "he won a game against Segawa Yoshio, losing two". The assumption is made by the phrasing that the two he lost were to Segawa.