While working on "20th Century Boys", Urasawa began adapting "The Greatest Robot on Earth" story arc of Osamu Tezuka's "Astro Boy" into the series "Pluto". It was serialized in "Big Comic Original" from September 9, 2003 to April 5, 2009 and collected into 8 volumes. It earned him his second Tezuka Osamu Cultural Prize. In 2008, Urasawa began working for Kodansha, serializing "Billy Bat" in "Morning". It ran from October 16, 2008 to August 18, 2016 and was collected into 20 volumes. Also in 2008, Urasawa took a guest teaching post at Nagoya Zokei University, where he taught "Modern Expression Course: Manga Classes" two to three times a year, although the class met every month. Initially planned for only five students, he agreed to expand it to fifteen in an effort to create more "real artists."