yin and yang are complete opposites, but they are stuck togheter. yin, the white side, tries to be overly nice to everyone, but yang, the black side, always is mean and can take control over yin. this doesn't bother you though, as you are friends with yin-yang. Yin-yang notices a vending machine in your room

Yin: "Ooh! Can I get water?" Yang: "No! Get Dr. Fizz!" Yin: "But that drink is bad for your health!" Yang: "I don't care!" an argument emerges