>>30311335Actually depends on your source.
Famitsu says X/Y's launch sold very slightly better than Sun/Moon in Japan, while Media Create says Sun/Moon sold better than X/Y in their respective first weeks in that country.
Media Create is generally seen as the more reliable source, but either way, their numbers are pretty even. Also, Sun/Moon is, in its first three days alone, already the #1-selling game in Japan in 2016, and it's not even close.
Regardless, Japan is but one country. Sun/Moon are killing the other 3DS Pokémon games in North America and Europe.