Ryuichi Kosugi (小杉 竜一, Kosugi Ryūichi, born 5 July 1973,[4] in Kyoto)[1] is a Japanese comedian who performs tsukkomi in the comedy duo Black Mayonnaise.
His partner is Takashi Yoshida.
Kosugi is represented with Yoshimoto Kogyo.
He graduated from Kyoto Prefectural Katsura High School.
[3] In 12 November 2010 Kosugi married a former dental assistant from Osaka Prefecture.