Sekai ni Otoko wa Jibun dake, Zensekai no Josei wo Ninshin Sasete Jinrui wo Sukue! Semen Caravan Nintei Soft  

世界に男は自分だけ、全世界の女性を妊娠させて人類を救え！　～ザーメンキャラバン認定ソフト～

Yesterday morning, I woke up with a severe cold. Upon waking up again, a healthcare professional informed me that everyone else had passed away due to an infectious disease. However, they told me that my sperm was the only remaining chance for humanity's survival.