Ok I'll try.
Basically hikaru and the mc were very close friends. And I'm pretty sure they had a crush on each other but I'm not 100% sure. Hikaru goes out one night takes a fall and ends up dying slowly. While he's dying he wishes the mc isn't alone. An unknown entity basically I guess heard this wish and takes over hikarus body and pretends to be hikaru.
I'm pretty sure the mc saw hikaru when he was dead...though I'm not sure I forget. But when the mc sees hikaru again he's confused and soon realizes it's not hikaru because it acts different.
The thing that took hikarus body is attached to the mc I'm guessing because it has hikarus memories and I'm pretty sure it has a crush on him.
The thing that took hikarus body is evil or a curse or something idk. I think that sums it up
I think the thing that took over hikaru is a curse or something. And they are kinda like exorcist the auntie and the other older guy (I guess he kinda looks like gojo) the gojo guy is like a main excorcist and the auntie just does it on the side. They both sensed something wrong with the town because of the cursed thing inside hikaru so they were trying to find it.
Hikaru and the mcs female friend can just see curses I think or sense them. So I think she sensed something wrong with hikaru and that's how she was able to tell it wasn't him
Hm, you quite did get it right. But some of it are not really y'know.
sorry if I sound rude:<
also please tell me if you still don't get it, I can help explain more in detail! ! !(≧▽≦)
The Auntie: She claims that she's just an ordinary housewife, but I think there is a twist to who she actually is, just a guess, but she does get rid of some of the impurities in the village; like the part where she shot an impurity right by the train rail(not sure if it's the name, I'm just thinking in my head trying to explain). She wants to help Yoishiki(mc) and Hikaru to solve how to get the impurities(the ghosts) away from the village without Hikaru getting sended back to the mountains.
The guy, he's basically from a company, and a psychic medium. He's not really an excorcist, both him and Auntie.
He was sent to the village because of the company. Since the company got interested or sumthn that was happening in the village.
Yoishiki and Hikaru's friend, Asako. She can basically hear impurities, what you explained on that she sensed that something was wrong with Hikaru was right, but she heard something different from him basically his voice. But she doesn't really know it's not Hikaru anymore, she thinks that it's still the old/real Hikaru.
That's all! ! !(づ ̄ ³ ̄)づ
I already read it until chapter 22, but I still can not understand about the storyT^T, like I understand but also confused :"