This seems like you are hunting ducks with a machine gun. shooting shooting, we have to keep this conversation based on the following Manga DOES DEAL WITH THE SUPER NATURAL, and DOES HAVE NO CHRISTIAN VALUES IN IT.
So the entire thread is based on a hypothetical situation that most or all manga has supernatural elements, except it's a completely false premise. Mecha series are usually totally devoid of the stuff, and are about as supernatural as Star Trek, with sci-fi technobabble explanations galore to lampshade anything that might be possibly construed as supernatural. Most school or slice of life romance, drama, or comedy series have little room for supernatural themes either. Those two segments constitute a significant portion of anime & manga.
If you're expecting an explicitly Christian message out of the entertainment of a country whose Christian population is about 2-3%, then of course you aren't going to find it. But that doesn't mean it contains 'values' that Christians would find offensive. Japanese media isn't a proselytizing tract, and Japanese culture actually tends to be
more conservative in some regards than Western culture is, and many times these crop up in their media they aren't defended with arguments from religion, if they're even defended at all.
GENERAL STATEMENTS, SHOOTING DUCKS AGAIN WITH THE MACHINE GUN, What percentage of Christian are we are talking about, and from what group of Christians, Menonites, Baptists Catholics? NO IDEA right this is a personal statement based in your tastes.
Arguments against fantasy fiction by some groups of Christians are usually supported by defenses from their own theology. The only ones that take the arguments that far are fringe groups, those who go way overboard when it comes to their worldview. The majority of the world's Christians fall into one of three categories - Catholic, Orthodox, or Mainline Protestant (for this purpose, consider Anglicanism to be Mainline Protestant), none of which adhere to the hyperspiritualized worldview that a small portion of Charismatics and Pentecostals, etc., do. Even most Evangelical and Fundamentalist groups acknowledge that there's a difference between fiction and reality in media; although they may object to certain things present in a story on a basis of influencing bad behavior (not because of a belief that it invokes spirits), they don't object to the medium as a whole. That's throwing the baby out with the bath water.
AND who said American Television is good for Christians? IF a book talks about a spirit guiding someone a Spirit which is not JESUS you are dealing with the occult!, about mental problems what came first the mental problem or the situation creating it?
I never said it was, I made that point because it's common to see people treat anime or manga as a single monolithic genre while openly conceding that it's plainly obvious that their own domestic media is diverse in theme. They also know that American media is a mixed bag, with some content being perfectly innocuous and some being sketchy or inappropriate, or that there are differing levels of appropriateness - what's perfectly fine for a 20-year-old to watch may not be appropriate for a 5-year-old. A kindergartener shouldn't watch the evening or 11 o'clock news, but that doesn't mean their parents or older siblings shouldn't.
If a book is fiction, the book is fiction. Fiction is fake, it's imaginary, and it's the last place anyone should be looking for theology or spiritual guidance. That's not the book's fault, that's the reader's fault for not thinking critically - those that do seek spiritual guidance in fiction are already mentally disturbed, it wasn't caused by the book. And overwhelmingly, anything that extremist groups deem to be 'occult' in fiction bears zero similarity to real occult, Pagan, or Neopagan practices and beliefs.
Fiction doesn't create mental problems, full stop. This is exactly what I was talking about in my previous post, because that same argument is used for far more things than anime & manga. It's a convenient scapegoat for those who don't want to face reality or don't want to see the warning signs when their 10 year old son or daughter is pulling wings off birds, but when they go on a shooting rampage at school at 16 and the media blames it on Call of Duty or Industrial music, they're perfectly content to jump on the video game/music blame bandwagon. If fantasy fiction really was a cause of mental problems, the rates of mental illness would be far, far, far higher than they are,
but they aren't.
This is a statement based on your personal opinion, when you take a child and tell him Santa Claus is coming down the chimny every Christmas night, he or she will believe that for years, Children believe anything and everything, they have no the "right and wrong" concept in them yet and they will believe that for years, if a commic book tell them you have an Spirit Guidance, and they read this very often guess what they will believe, that's why in my church Manga an animate are banned and the majority of comic books. As a matter of fact my children don't believe in Santa Claus.
Most comic books, anime, and manga are intended for teens and older, and lacking the ability to discern proper appropriateness is the fault of the consumer, not the media. Teenagers are not children, and even at that, it's rather insulting to the intelligence of actual children to assume that they don't know when something is make believe or not, or that they're all gullible suckers, or have no internal moral compass. If parents actually do their jobs and teach their children when something is make believe from a young age, they are more than capable of using their brains and not buying into everything they're told. The same thing goes for teaching them right from wrong - which they should have been learning by parental example for the first 5 or 6 years of their lives.
Also the whole Japanese society practice in one way or another the Shinto Religion. Years ago when I was working for a Botanical Garden (not allowed to mention name), here in the States, they hired a gardener from Japan to make a Japanese Garden ( a real beautiful one, he did a great job.) In the middle of the garden is a big stone, the size of a Cocker Spaniel Dog, he never moved because the Kami did not allowed. This guy later I found out he was not religious at all, but believe it in Urarina Myths, wish give to inanimate objects and animals a spirit wish you have to consult all the time ( Japan is not a real Secular society is Secular in their documents of government and Constitution, because their were concerned during Second World War of the Allies wish they were mainly no Buddhist or Shinto Religion at all, Japan is mainly Buddhist and they also practice the Shinto Religion, a lot of my Japanese friends do practice both. But going back to your statement Children have no concept of Real and Unreal...
Many of the precepts about Buddhism or Shinto are culturally-intertwined, so something that occurs is not necessarily because of a deeply held belief, just like some of the culturally-ingrained things we do here in the West that may have had some religious (Christian or otherwise) meaning to it at some point in time but is now just a superstitious fragment with no real weight of belief. There are plenty of cases - even in anime and manga - that make reference to Japan as an atheist or secular country, or that actual religious views are highly syncretic.
It would not be wrong to state that religious adherence in Japan is highly likely to be of a cafeteria sort - show up, perform your community responsibility to save face (because Eastern society is much more community-centered than individualistic), and go home, with only an extremely rudimentary knowledge of the religion they claim to practice. I'd venture to say that a lot of attendance at Shinto shrines falls into this category - being a tradition to visit for New Year's or for good luck, with non-attendance or refusal highly discouraged by society, or for totally non-religious tourism purposes.