NSP files are a format used by the Nintendo Switch for distributing and installing games. While it's technically possible to obtain NSP files through legitimate channels (such as purchasing a game digitally), unauthorized NSP files are often discussed in online communities.
: Verified sellers often list authentic physical copies, though you should check seller ratings and product authenticity. Amazon.com About the Grand Edition Diabolik Lovers: Grand Edition for Nintendo Switch Diabolik Lovers- Grand Edition Switch NSP Free ...