Sure, Pokemon Sun and Moon just came out last year, but Pokemon Ultra Sun and Ultra Moon still have that heat. According to Famitsu sales numbers (translated via Gematsu), the combined release sold 1,199,814 copies during their first three days of release in Japan. That number isn't officially from Nintendo, so it doesn't include download sales.
The Nintendo 3DS family of consoles, which currently includes the New 3DS, New 3DS LL, 2DS, and New 2DS LL, sold 40,582 copies during the week (November 13 - 19). That's way up from the previous week's 18,687 units and it is likely attributable to Ultra Sun and Moon's release. Unlike last year, there was no special branded 3DS unit for Ultra Sun and Moon.
Our own Kat Bailey is playing through the game right now, but it's been slow going since a large part of Ultra Sun and Moon is just the original release.
"Pokemon Ultra Sun and Ultra Moon has no such additions to its presentation (unless you count the souped up music); and having played through the originals just last year, I've been beset with a sense of deja vu. I'm always in a bit of a rush to finish off the story, but it's been worse than usual this year. It's been tough to get motivated enough to want to continue," Kat wrote.
Pokemon Ultra Sun and Moon is out everywhere for 3DS.