I'm confused at why people are confused by this?
This is just "codependency the manga". These five are magical(?) and go into dangerous outburst if they stray from one another, as demonstrated by Mana and that big ass hammer.
I'm intrigued to see how this will go. There will obviously be drama, but how much? Also, if no one dies in this I call bullshit. Teenagers with raging hormones are dangerous, these guys basically had powers to squash other human and them not accidentally killing anyone is unbelievable lol.