The town SunnySide is a blend of a few different cities: Iwanai/ Kyowa area, Suttsu, and Setana... all of which are in Hokkaido. The City of Higashi was modeled after a very specific street in Sapporo.との回答。(2024.3.30)
1分51秒に土肥特産市ありがとうが出てくるので断定できた。リンク先の伊豆市 観光情報 特設サイトを引用する。(I was able to determine this because the 土肥特産市ありがとう appears at 1:51 minutes. To quote from the linked Izu City Tourist Information Special Site.)
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