> Note that Japanese reviewers are substantially pickier than you are No kidding, I see lots of reviews like: food is tasty, service was friendly, price reasonable. 3 stars.
And American reviewers are pretty much the most generous out there. My rule of thumb is that a 3.5 rating by Japanese equates to a 4.5 rating by Americans. Seriously.
5 stars: "it was amazing"
4 stars: "really liked it"
3 stars: "liked it"
2 stars: "it was OK"
1 star: "did not like it"
I wonder how many people, without any other context, would interpret "I'd rate this book 2 out of 5 stars" as "yeah, it was OK".