During this traditional festival to send off the spirits of the dead, small ceremonial lanterns will be sent to float downstream. The lights of around 1,000 lanterns will glimmer in the waters of the Serikawa River, a magical scene representative of summer in Japan. Functions like these, held in honor of the dead, have been passed down in many regions, and have ancient origin in the Buddhist Ullambana Sutra. Participants in this festival light lanterns by the riverside, and send them down the river to comfort the spirits of the dead.