Gokurakuto monogatari is a Japanese movie of 9,151 characters, with 1,107 unique words and 523 different kanji. Its difficulty rating on Jiten is average, 2.5 out of 5. The full vocabulary list ranks all 1,107 words by how often they appear, and you can study them on Jiten or download them as an Anki deck.
Here are some of the words that appear most often in this media, as well as a sample of its rarer vocabulary.