Detective Pikachu doesn’t arrive until later this month, but Nintendo 3DS users can now try it out via the special demo version in Japan. The Detective Pikachu demo allows you to play a portion of the main story from the beginning. In addition, your saved data can be carried over to the full game when it launches on March 23. To download the demo, you can use your Nintendo 3DS to snap the above QR code to take you to the title’s official page in the Nintendo eShop. It requires a total of 1,765 blocks of free space – which equates to about 220 MB.
Source: Official Pokémon website