Tenmon (天門) (stylized as TENMON) born Atsushi Shirakawa (白川篤史, Shirakawa Atsushi), is a Japanese music composer from Tokyo, Japan born October 4, 1971. He worked in the Nihon Falcom Corporation as one of the members of Falcom Sound Team J.D.K.. During his time with Falcom, he has composed much music for Falcom games, most notably Brandish.

Having known Makoto Shinkai as a coworker in Minori he has composed music for Shinkai's works since She and Her Cat. He is perhaps best known for creating the soundtracks for Shinkai's subsequent works, Voices of a Distant Star, The Place Promised in Our Early Days, 5 Centimeters Per Second and his final Shinkai collaboration being Children Who Chase Lost Voices from Deep Below. As of 2019, he has joined CoMix Wave Films, but no further information is available about what he has done with them since; latest news indicate that he will not be reuniting with Shinkai for Suzume no Tojimari.