From Episode 2 on you can automate your Hangouts. Automated Hangouts don't require you to manually collect their production while the game is open and they will keep producing Cool Points even while you're away from the game.
Each Hangout has its own automation requirements, which vary according to the Episode you're on. You will first need one specific Character to be unlocked and at a certain level. If you meet that condition, all you have to do is pay the required Cool Points.