For those interested in playing the Japanese version of Yokai Watch 1 on their Nintendo Switch, the NSP file is the package file used by the Nintendo Switch to distribute and install games.
You're looking for information on Yokai Watch 1 for the Nintendo Switch, specifically the NSP (Nintendo Switch Package) file for the Japanese version (JPN) with English support (U). yokai+watch+1+for+nintendo+switch+nsp+jpn+u
The first game in the series, Yokai Watch, was initially released in 2013 for the Nintendo 3DS. Later, a port for the Nintendo Switch was released in Japan as "Yokai Watch 1 for Nintendo Switch" (). Although it's been a while since its initial release, the game remains a great introduction to the series. For those interested in playing the Japanese version