If you’ve been playing Mario Tennis Open on your 3DS, then you probably know that you can unlock different costumes and characters. Some of these were made available on various websites after the game’s launch. Don’t feel like tracking them all down now? Don’t worry, thanks to Reddit user Girolmao, they’re all in one place.
There were a total of 9 QR codes released; one costume, and 8 characters. The costume is a green Yoshi, seven of the characters are different colored Yoshi, and Metal Mario.
In order to use the codes, you’ll need to open the game. You won’t be using the regular QR app for the 3DS. Then, when you’re at the screen where you select a file, hold UP on the D-pad and press start. Your camera will turn on, and you’ll just need to line up the code inside the box. The new item will then appear in each of your current save files.