Mike and Sulley are inseparable, but that wasn’t always the case. From the moment these two met they couldn’t stand each other. “Monsters University” unlocks the door to how Mike and Sulley overcame their differences and became the best of friends. “Monster University”, the highly-anticipated sequel to Pixar’s 2001 hit “Monsters, Inc.”, opens in theaters on June 20th, 2013. Check out the teaser below.