On page 16, with the way the Sunglasses Investigator spoke about the Great Brainsnatcher and his Company makes me question the nature of this story and if instead of Supernatural it's extra Extraterrestrial with how he spoke about centuries-long research and the source being from "beyond this world". It might be less Old Japanese Gods and more Lovecraftian Outer Gods with the village and surrounding mountains being a kind of Skinwalker Ranch.
Anyway, I was surprised 'Hikaru' woke up but he may not be himself in the last page. I bet the piece of himself he gave to Yoshiki will be critical to a full recovery. Thanks for the TL!