was the first Japanese astronomer to discover an asteroid. In 1900 he discovered 498 Tokio and 727 Nipponia. The crater Hirayama on the Moon is jointly named after him and Kiyotsugu Hirayama. References External links 月の命名は？ at www12.plala.or.jp (in Japanese) 1868 births 1945 deaths 19th-century Japanese astronomers Academic staff of the University of Tokyo University of Tokyo alumni 20th-century Japanese astronomers