- Extract your save with a homebrew (JK's Save Manager or other)
- Open sysdata.dat, edit
- Re-import your save with a homebrew (JK's Save Manager or other)
- Edit Money
- Unlock all items by numbers
- Edit interiors designs
- Edit animals names
https://github.com/Brionjv/3ds-Nintendogs-cats-Save-Editor/releases
https://gbatemp.net/threads/release-3ds-nintendogs-cats-save-editor.473694/