Baitosaki ga Make Heroine-tachi no Tamariba ni Natta is a Japanese novel of 256,054 characters, with 10,669 unique words and 1,882 different kanji. Its difficulty rating on Jiten is hard, 3.3 out of 5. The full vocabulary list ranks all 10,669 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.