Factual error: Throughout the film, most Japanese words are spelled in Katakana. In real-life Japanese, however, Katakana is exclusively used for foreign words adopted into Japanese language, like 'table', 'television' (mostly it is abbreviated to 'telebi') and 'racing car'. But in the film, even indiginous Japanese words such as 'samurai' are spelled in Katakana, not - as they should be - in Hiragana (the syllable system used for native words).
Continuity mistake: When Raven is attacked by the shadow creature in the graveyard, it leaves a number of smears (ink) on her cloak. But as she proceeds to phase through the tombstones in an attempt to shake it off, the smears have vanished.