
Hitotsu Yane no Shita de Kurasu Kanpeki Seiso Iinchou no Himitsu wo Shitteiru no wa Ore dake de Ii. is a Japanese novel of 83,737 characters, with 5,343 unique words and 1,378 different kanji. Its difficulty rating on Jiten is average, 2.5 out of 5. The full vocabulary list ranks all 5,343 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.