Masato Shimon (子門 真人 Shimon Masato?, January 4, 1944–) is a Japanese vocalist from Meguro, Tokyo. He is most known for his contributions to the theme songs of various anime and tokusatsu series. In his career, he has sung under the names Kouichi Fuji (藤 浩一 Fuji Kōichi?), Akira Tani (谷 あきら Tani Akira?), and Ryū Kisami (希砂未 竜 Kisami Ryū?).