Japanese nationalism
Sugiyama is also a council member of the Japanese Society for Rights of Authors, Composers, and Publishers (JASRAC), board member of the Japan Institute for National Fundamentals, and honorary chairman of the Japanese Backgammon Society. He was named a Person of Cultural Merit by the Japanese government in 2020. Sugiyama also engages in activism outside of music, such as the denial of Japanese war crimes and the promotion of Japanese nationalism.