Kotaro, who had to redo his final year at Tsurugamine High School, discovers Judo through his encounters with first-year students Kumi Mifune, Sanshiro Saigo, and Daigo Daigo. Although Kumi lost to Kotaro, she decides to learn Karate to defeat him. However, delinquent Judoka Daigo captures Kumi to use as bait to take over Kotaro's Kyokutan dojo. Sanshiro is also taken and the Judo Club becomes embroiled in the conflict with Kotaro.
This new arc, which brings back previous characters and introduces new ones, takes Kotaro and Mayumi into the world of Judo, where they encounter comedic and ecchi situations mixed with martial arts.
