2020-12-31 訃報 of the year 訃報 志村けん (Feb 20, 1950 - Mar 29, 2020) John Horton Conway (Dec 26, 1937 - Apr 11, 2020) 岡江久美子(Aug 23, 1956 - Apr 23, 2020) 小柴昌俊 (Sept 19, 1926 - Nov 12, 2020)(敬称略)