The VIP system is strictly tied to how much you've purchased in the game using Nutaku coins.

There are a total of 12 VIP levels, each providing a wide variety of daily rewards, some weekly benefits, and more. For more info, you can press the VIP button on the top left corner of the screen.

By pressing "?" you can see how much Nutaku gold you need to spend to reach the next VIP level. Increasing your VIP level also unlocks more missions in the weekly missions area.