Hiroshi "Monsieur" Kamayatsu (かまやつひろし ( January 12, 1939 – March 1, 2017) was a Japanese singer and guitarist. Born in Tokyo, "Monsieur" has been a founding member of bands The Spiders, Vodka Collins, and also a solo act. In recent years he had a reunion with some former members of The Spiders, as the band Sans Filtre. Among his recent work is his performance of the song "RTB", the ending song to the anime Sentou Yousei Yukikaze. He has been performing for over five decades. He died from pancreatic cancer on March 1, 2017.