Antonio Jr., the son of the yakuza boss Shachou's cat Antonio Sr., pursues revenge against Kotetsu. His father sustained severe injuries, including partial castration, in a fight with Kotetsu and later died after an encounter with a dog while still weakened. Antonio Jr. confronts Kotetsu at Shachou's okonomiyaki restaurant, demanding a fight. Kotetsu refuses combat, showing respect for the deceased Antonio Sr. This display of respect causes Antonio Jr. to forgive Kotetsu and abandon his quest for vengeance. The conflict ends peacefully, with both cats and their humans returning home. Antonio Jr. appears in the sequel television series "Chie-chan Funsenki Jarinko Chie," which adapts further storylines from the original manga.