Obon toro-nagashi.

More about Obon toro-nagashi.

Obon (お盆) is a Japanese Buddhist festival, held in the summer, during which people honor their ancestors and departed loved ones. It is believed that during Obon, the spirits of the dead revisit their families. Rather than being a dark or sinister event, this festival is a happy celebration of family unity and continuity. It begins and ends with bonfires: mukaebi (迎え火 or “welcoming fires”) and send-off fires called okuribi (送り火) which are lit to guide the spirits back to the world of the dead. Also the end may include a special kind of send-off fire called toro-nagashi (灯篭流し). These are floating paper lanterns with candles inside which are released onto rivers or the sea. (Important note: Obon doesn't usually include sky lanterns, but the AI was insistent. There is a more modern, secular, summer festival held in a few Japanese cities called the Tanabata Sky Lantern Festival in which thousands of sky lanterns are released on one night.)