I believe this is a Tenpo Tsuho coin, but I don't know anything about its value. Would you be interested in it for your collection? I received it from a 99-year-old this year, and I'm selling it because I don't use it. They said they found it under a building in Arakawa Ward during the Great Tokyo Air Raid. - Shape: Oval - Material: Metal - Features: A square hole in the center - Decoration: Old characters and patterns are carved on it - Condition: Shows weathering due to age Thank you for looking.