The currency in this game are cash and k-gems.
Cash is the standard currency that you earn throughout the entire game while filming, completing quests, etc. It is used to travel, buy clothing, houses and furniture.
K-Gems are the hard currency that is earned slower than cash and has a more incentive of being bought with real money. They are used to purchase special outfits, energy, cash, or to get some special advantages in the game.