The Quarrel Festival (けんか祭り, Kenka matsuri) is an annual celebration depicted in Konoha Shinden. Dog-lovers more commonly call it the "Dog-Cat Festival" (犬猫祭り, inuneko matsuri), while cat-lovers more commonly call it the "Cat-Dog Festival" (猫犬祭り, nekoinu matsuri).
In a town that lies on the border between the Land of Fire and the Land of Hot Water (and therefore can't be said to truly reside in either country), there are competing stories about how the town was founded. Some say that the town's hotspring was dug up with the help of a dog god (犬の湯, inu no yu). Others say that the town's hotspring was dug up with the help of a cat god (猫の湯, neko no yu). While the townspeople generally believe both stories are true, they are bitterly divided over which of the town's two hotsprings was discovered first.
The townspeople set aside their differences for most of the year, cooperating on issues and getting along peacefully. But once a year they celebrate the town's founding, wearing either a dog or cat mask in honor of their preferred deity. Over the years, the resulting Quarrel Festival has become an opportunity for dog-lovers and cat-lovers from all over the world to come together and compete for superiority. Fights inevitably break out and some amount of injuries are common.
The Quarrel Festival is seemingly brought to an end - at least as it was - by Mirai Sarutobi. After hostilities once again break out between those loyal to the cat and dog deities, Mirai casts a genjutsu before the townspeople to create a giant head that is equal parts cat and dog; the assembled crowd dubs this illusion "Cattog" (ネヌ, Nenu), the town's rumoured third deity who mediates between the cat and dog gods. Mirai, via Cattog, tries to advocate peace, but she makes little progress before the illusion is attacked by a fearful Might Guy. In the process, Guy destroys the wall separating the town's cat and dog hotsprings, combining them into one. The townspeople interpret this as an act of Cattog, his wish that they stop fighting, and decide to worship him henceforth.