Kokoro Connect is one of the best high school anime ever made. It's too bad it didn't get more seasons.
Make sure to watch all 17 episodes. Unfortunately, Crunchyroll only has the first 13 episodes.
So far there seems to be no way to legally stream episodes 14 - 17 in the US. Netflix Japan has all 17 episodes.
The good news is the blu-ray of episodes 14 - 17 (also known as OVAs) is only $2.99 at the Sentai Filmorks shop.