Five students (Two male, three female) form a club to satisfy school policy. Then, without explanation they begin to switch personalities. Thus is the start of the anime series Kokoro Connect.
The show starts out with two of the students, Yui Kiriyama and Yoshifumi Aoki trying to explain to club president Iori Nagase and other club members that they had switched bodies the previous night. Of course they aren't believed until the same phenomenon starts to the others as well.
Of course, it pretty much goes without saying the problems that occur considering the gender difference. Bathroom use and unaccustomed body parts are the first thing addressed right from the start. No surprise there.
While trying to discuss what to do about the situation, we are introduced to "Heartseed" a spiritual being, who has taken residence in the body of one of their teachers. He explains that they are set with a undefined task that they are to fulfill and just to go on about their lives.
One of the big problems early on with this show is that the swaps happen without rhyme or reason, so getting the characters and their traits straight can be a chore. This is kind of a turn off for anyone who doesn't want to put too much thought in their anime watching. Thankfully, it mangages to work itself out as the series continues.
Of course, the situation gets sticky when the male students Taichi Yaegashi and Yoshifumi are caught filming themselves giving fake love confessions while in female students Yui and Himeko Inaba's bodies. To make things more complicated, Yui has a fear of men due to a past trauma.