Certainly not a work which will satisfy everyone's senses. Not only is it initially abstruse in its presentation, but its esoteric nature could repel casual readers and those who'll dive into it with expectations of a typical horror work.
It blends myths from Buddhism and early Jomon and Yamato cultures with intent to tell story of a certain boy's divine journey. Problem lies in educational input which breaks immersion and makes the reader feel like in the middle of a lecture. Abundance of various traditions, names and places, accompanied by substantial explanations makes it feel like a chore you need to endure to finally proceed with actual story. Of course, some readers could find it enjoyable to learn about different myths and perhaps end prompted to explore them more meticulously, thus further elucidate the intricate story.
Important to mention, are evident Lovecraftian influences manifested in the famous fear of the unknown, which is present from the start to the end. It certainly adds an enjoyable dose of macabre, and will make fans of the aforementioned author feel at home.
Morohoshi's art style doesn't quite shine as far as depictions of characters are concerned. At some parts they even appear rushed. Reason for this is that he focuses more on creation of an eerie atmosphere, so expect to see some very detailed elements that pertain to overall sense of horror, such as statues, various monstrosities and symbols.
Characters in this work are more or less consolidated in their roles of a plot tools. Some of them succeed to arouse interest to a certain point when you realize no extraordinary development was ever intended. I can't say that it harms the overall impression much, but other way around would have definitely improved it.
All in all, it is a commendable fusion of facts and fiction. If only Morohoshi focused more on the presentation and extended work to a couple more volumes; that would have made narration easier to follow as opposed to this questionably tolerable and condensed outcome.