
After saving the world by defeating the Demon Lord, the strongest hero Leo became unwanted in the peaceful human kingdom because they feared his power. Exiled, he sought a job with the Demon Lord's kingdom, which needs to be rebuilt after its defeat. The army and kingdom had many problems: lack of manpower, financial troubles, etc. Leo started to make improvements using his power and experience. When Leo encountered Echidna again, he asked her why she invaded the human world. There was an unexpected story---! (Source: Kadokawa, translated)
Yuusha, Yamemasu: Tsugi no Shokuba wa Maoujou is a Japanese novel of 381,310 characters, with 14,545 unique words and 2,169 different kanji. Its difficulty rating on Jiten is hard, 3.4 out of 5. The full vocabulary list ranks all 14,545 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.