I was almost 100% sure that this was a much older show than the Wikipedia article suggests - was there another show with a similar name a few years ago? Or maybe I'd seen something about the light novels this was based on.
I don't really understand what it is about (primarily romantic) high school anime that gets its hooks in me like this. The social structure is different from what I experienced at school; the culture of clubs and groups is different, we never had a student council with its fingers in everything, and there's something slightly weird about how all the schools in these shows have the exact same classrooms, staircases, staff rooms and rooftops, and the same lockers in the entrance hall1. They're familiar places after you've seen one show, no matter what year or which part of world the next one is set in.
The main benefit of this familiarity, for a western viewer, is that you instantly know where everything's taking place. You have a sense of geography right away, which lets you concentrate on what's different about this particular show.
Kokoro Connect follows the experiences of the five members of the Student Cultural Studies club as they're experimented on by a powerful intelligence that calls itself Heartseed, beginning with apparently random instances of body-swapping but soon moving on to more emotionally perilous tests. The members of StuCS are forced to face their own - and their friends' - darker sides and insecurities that are brought to light as a result.
This show could be a lot darker than it is. Having teenagers swap bodies obviously has some potential for serious mischief, but the show manages to keep its mind mostly out of the gutter. The second of Heartseed's experiments, which is constantly and distractingly referred to by the characters as "unleashing desires", has even more dangerous possibilities - although aside from the very first instance there's nothing risque, and there doesn't seem to be any clear indication of when anyone - apart from Taichi, ostensibly the main character2 - is actually suffering from an "attack".
It's this second part of the show that's my favourite; the body-swapping is kind of fun and does actually come closest to the sinister ideas that could have been much more common with the material, but the group dynamic changes much more as a result of the "unleashed desires" problem and it's an interesting stress to put on a group of people who are really only friends by chance. It forces them to reassess their relationships and causes some promising conflicts, although once it's all over there's really only one character with a long-term change as a result - though they are in position to have a sizeable impact on (at least two of) the others.
The romance plot is one of the weak links for most of the early episodes, but a development towards the end of the second experiment does shake things up a bit3. It also makes the earlier, token confession stuff more worthwhile and results in higher stakes and one of the most emotional scenes in the show. It's a shame that, as with a lot of the fallout from these experiences, the status quo in the group isn't disturbed much by this shift. It'd be nice to see more realistic reactions to these events, rather than either no reactions or melodramatic self-exile.
1 These might be accurate depictions of schools in Japan - a lot were probably rebuilt after World War 2, which would explain the almost-identical architecture.
2 I'm strongly of the opinion that Inaban is actually the main character, as she's the only one who seems to go through any kind of meaningful character development as the series progresses.
3 I'm trying to be vague, but making sense is proving difficult. Unlike Sword Art Online I think this one's actually worth watching, though - so I don't want to spoil anything.