Depends on how you define it. I view naizuri as anything where the breasts aren't big enough to fully wrap around the circumference of the dick.
Updated
Like, sure, Reimu's breasts are b-...bigger than mine.But I've still got enough to wrap you up.So I'll mess you up so bad with my boobs, that you finally get that I'm way more bewitching.So check yourself.
before you wreck yourself.*squeeze*♥*rub*♥