This traditional summer festival has been held for over 100 years since 1906, and is representative of Onuma. It began when a local priest floated lanterns on the lake to offer prayers for those who had drowned. At the annual memorial service, lanterns are floated on the lake to honor those who had drowned, those who had recently passed away, ancestors, and pets. There is also a fireworks display over Lake Onuma and various other events that the whole family can enjoy. Anyone can participate in the floating lanterns.

■Saturday, July 26th
There will be a live stage performance of "Yosakoi" and dancing by local children, street performances, a memorial service and a floating lantern event.

■ July 27th (Sunday)
There will be a brass band performance, magic show, Tsugaru shamisen stage and fireworks display. "Onuma Ruche" will also be held at the same time, where locally grown vegetables, sweets, handmade items and more will be gathered.