Dungeon de Tatakaitsuzukete 20-nen no Doutei Yuusha, Chijou ni Modottara Danjoubi 1:1000 no Sekai Datta

The Virgin Hero Who Fought in the Dungeon for 20 Years Returned to the Surface Only to Find the Population of the World Has Dropped Drastically • With a Male-To-Female Ratio of 1:1000 • ダンジョンで戦い続けて20年の童貞勇者、地 上に戻ったら男女比1:1000の世界だった