Factual errors (feel free to add yours)
As someone who lived in japan for a couple of years:
-Japanese taxi drivers ALWAYS wear white gloves (same goes for bus/train drivers, pilots...etc.)
-Japanese medicine doesn't come in small plastic jars like in the US. Hospitals give you blister packs bagged in a paper bag with your name on it. Also everything is written in Japanese (duh).
-I've never seen a stone wall basement in Japan. Basements are not a good idea when you live in a country with such an important seismic activity. (I'm not saying there are no basements/underground facilities in japan though)
-There is no way an information center would casually store bodies in the basement. In many countries, including Japan, you need a license to handle dead bodies.
-I understand it's for the sake of the plot but Japanese people would probably be very reluctant to guide foreigners to such a place because it's a common belief foreigners are disrespectul of/can't understand their traditions. (I don't think they would ever agree to let people shoot a movie there)
Few years ago foreigners were banned from entering Tsukiji market for a while after some foreigners messed around with the equipment and disturbed the workers. Even though it's illegal, some shops/places hang a "no foreigners" sign on their front door.
- Considering how superstitious Japanese people usually are, I highly doubt anyone would touch/move a dead body, especially without saying a prayer or something.
-Again, it's probably for the sake of the plot but most Japanese people don't speak very good English, especially outside of Big cities and Okinawa.
It's not a factual error but who on earth would be stupid enough to go hiking in a forest with no map, no flash light, no hiking shoes or protecting gear?
Japanese forests = mosquitos, leeches and mukade (centipede)