Every autumn, the sleepy mountain hot spring town of Yamanaka-Onsen transforms into a two-day party called Koi-Koi Matsuri, which roughly translates to “Come on Come on Festival.” All over Japan, events like this coincide with the reaping and threshing of rice crops. Though it has its roots in the area’s agrarian past, Koi-Koi Matsuri resembles a carnival more than an ancient harvest rite. Traveling vendors with brightly colored banners line the streets, selling sweet baby castella cakes, miniature okonomiyaki, and all sorts of novelty snacks-on-a-stick glistening with salty-sweet sauces. (When this festival is done, the vendors will pack up and head to the next town’s celebration.)

Pop music that’s broadcast from a tower-like circular stage in the town plaza blends with the more traditional aspects of the festivities. Lion dancers roam the streets, performing in front of homes and businesses that give them money for good luck. Neighborhood groups and professional cooperatives gather in a pop-up party headquarters called honjin, drinking the local sake, Shishinosato, in tents and garages.

Yamanaka is known for two things: onsen (hot springs) and shikki (wooden lacquerware). On the second afternoon of Koi-Koi Matsuri, rowdy groups carrying mikoshi, portable shinto shrines, gather in the town square to be blessed with a splash of onsen water. In addition to typical festival mikoshi—ornamented in gold and swaying tassels—Yamanka has one shaped like a giant miso soup bowl. Twenty-some shikki craftsmen march the enormous owan (soup bowl) mikoshi through the town. After parading between a truck full of geisha singing folk music, and rowdy 25-year-olds hoisting a dragon-mikoshi, they’ll put away the giant bowl and head to their honjin to party into the night.

The next morning, the vendors are gone and the streets are clean. The town is especially quiet, because everyone is hungover.