The chapters of the Japanese manga series Big Windup! are written and illustrated by Asa Higuchi. The series has been published in Kodansha's manga magazine Monthly Afternoon since September 25, 2003. Kodansha has collected its chapters into individual volumes, with the first one released on March 23, 2004. As of June 23, 2025, 38 volumes have been released. The series follows Ren Mihashi, the previous ace pitcher in his middle school's baseball team, who suffers from low self-esteem due to a losing streak and transfers to a new high school. It is the first year that Nishiura high school has a baseball team, and they set a lofty goal of playing in the finals at legendary Hanshin KÃ Âshien Stadium.