The Summer Hikaru Died Vol.1

Something's up with what seems like Hikaru. It's like Hikaru is using the body that used to belong to this boy, even though Hikaru is no longer around. Now, there's some weird force that's taken over the boy's body. And get this - Hikaru's best friend, Yoshiki, senses that things are off even before this entity spills the beans that it's not really Hikaru.