Talk to the Lady in Battle Resort for :
Battle Resort Theme
VS Wally Theme
Victory Road
"Come Along"
Super Secret Training
Get Silver Rank for Secret Bases
![enter image description here](https://i.imgur.com/2fgl21t.png)
Progress further into the game
You get 4 pieces at the start. You can unlock more as you get further in the Game
![enter image description here](https://i.imgur.com/7pWEcto.png)
Source