Its unknown how Gold Silver sold in its first 11 weeks but New Horizons certainly has the record for everything after that.
I checked here and Gold/Silver only sold less than 100k after 12 weeks: https://www.vgchartz.com/weekly/36569/Japan/
(the 1st week didn't count, because it was the launch week: https://www.vgchartz.com/weekly/36485/Japan/ )
If Animal Crossing stays at least another week over 100k, it could break that record (although sales are not as high as Gold/Silver, which by now had reached 6,3kk).
It sounds good when you say "For the People", but what you really want is... a stronger army than the Knights, and the evil power to control the people.
(Ramza Beoulve, Final Fantasy Tactics)