Maru Sankaku Shikaku ("circle", "triangle", "square") was a psychedelic group active between 1970 and 1973, led by Sakuro "Kant" Watanabe.

They released five records in 1973, each containing two side-long jams, most of which have been summarized on the 3-CD set Maru Sankaku Shikaku (Captain Trip, 2002). Theirs was an ethnic, mystical experience, that embraced the late hippie spirit of Taj Mahal Travelers and Third Ear Band.