It has always amused me that the tourists to the US that I’ve spoken to are often very excited to see raccoons, and disappointed if they don’t see them before they leave.
Some others I’ve noticed on the east coast of the US are blue jays and cardinals. Boy, do people get excited about those if they’ve never seen them before! Very pretty birds of course, just very easy to get used to and see as uninteresting as well.
I’m not Japanese but have been living here most of a decade. As no one mentioned anything from that side yet, the Nara Deer are probably the most famous followed by the hotspring monkeys. Tanuki are also something people might want to see, off the top of my head.
My wife was super surprised by all the squirrels in the US and loved taking pictures and videos. She suddenly realized we kept seeing more of them as we walked and, yep, they’re everywhere.
She was also super surprised that people just had cattle and horses when we’d be driving where my US family lived (countryside).