First day covers from various genres issued between 1991 and 1992. 〠January 1991: Horse and Culture Series Postage Stamps, Vol. 4 〠May 1991: Postage Stamps Featuring Winning Designs from the 2nd Postage Stamp Design Contest 〠July 1991: Commemorative Stamp for the International Conference on Superconductivity 〠April 1991: Commemorative Stamp for the Launch of the New Simplified Life Insurance System 〠August 1991: Commemorative Stamp for the 3rd World Athletics Championships Tokyo 〠August 1991: Commemorative Stamp for the International Conference on Environmental Change and Geographic Information Systems 〠October 1991: Furusato Stamp "The Hare and the Tortoise" (Gunma Prefecture) 〠March 1992: Commemorative Stamp for the 8th Conference of the Parties to the Convention on International Trade in Endangered Species of Wild Fauna and Flora (Envelope included) 〠April 1992: Postage Stamps Commemorating Stamp Hobby Week 〠August 1992: Commemorative Stamp for the 29th International Geological Congress 〠November 1992: 41 yen, 62 yen, and 72 yen definitive stamps