This is very very weird, also very gay in a interesting way.

So basically the guy on the cover, Hikaru is dead, and yet he's walking around school and talking to people. His best friend knows he's dead and this creature or whatever has taken over his friend's body. And so he puts up with it, since this monster remembers Hikaru's memories but it isn't him. And our lead is also obviously in love with Hikaru, and there's a touching inside the creatures chest that's extremely sexual, but the faces are horrifying, and it's just a weird as fuck manga but still I'm intrigued where we go but don't 100% invested.