Complex sentence: Adult animation is known in Japan as アダルトアニメ (adult anime), but animated works of a sexual nature are described in western fandom as hentai, the Japanese word for' perverted.
Split into simpler sentences: Adult animation is known in Japan as アダルトアニメ (adult anime). Animated works of an erotic nature are often described in western fandom as'hentai,' the Japanese word for' perverted.