You already know that once a Tamagotchi Friends grows up to a teenager at about 1-2 years, it can go to the Dream School. At Dream School you can choose witch class your Tamagotchi can do. All the classes are simple mini-games, and if you play a class more then others, then you will have that class as your favorite, or the class you are best at. You can see your "best class" on the second page of the information tab. you're best class will also effect what type of Tamagotchi you're going to get once it grows into an adult. You can see on a growth chart, that how the Tamagotchi looks will give you an idea of what kind of Tamagotchi you might get next. So if you are the best at the Robot class, then you might get a futuristic spacey kind of Tamagotchi.