Kokoro Connect is a series I decided to watch on a whim after spotting it in CrunchyRoll one day, and I'm certainly glad that I did.
I felt like the story was, by far, the stongest point of the series and what made it stand out from your average high school romance/drama anime. While the audience is never given a full and proper explanation of why the main cast suddenly find themselves swapping bodies with each other, reading the others' thoughts or acting on their supressed desires, among other things, all these events are handled really skillfully to flesh the series' themes out.
All the apparently bizarre happenings have something in common: They force the main cast to lay their innermost emotions and struggles bare for their friends to see, no matter how much they might try to normally hide that side of them away, which is what prompts the others to try their best to help.
The way each character's problems were addressed was nice, and the characters felt relatable at most times. There were a couple of overly dramatic moments here and there, but I still felt like they worked well as set-ups for some really cathartic moments at the end of each arc.
I've also got to commend the series on how it managed to ease the tension with comedic scenes that didn't amount to pandering to the audience. While there were a couple of scenes that stuck out as weird to me, I liked how the show was serious whenever it was addressing somebody's problems rather than just laughing them off with trope-ridden scenes.
About whether I'd recommend this series or not, I'd say it depends on how much you care about series focused on character drama, since Kokoro Connect leans heavily on that. It felt like it didn't care all that much about explaining the bizarre happenings as much as it waned them to be there in order to explore each character and the bonds they make with their friends as a result of these trials they're put through.