OSM tag name=伊豆沼 matches 伊豆沼 in these Wikidata fields:
OSM tag name:ja=伊豆沼 matches 伊豆沼 in these Wikidata fields:
OSM tag name:en=Lake Izunuma matches Izunuma in these Wikidata fields:
OSM tag name:ja-Hira=いずぬま matches Izunuma in these Wikidata fields: