
Why are we doing this...? When Haruhiro came to, he was in the darkness. Not knowing why was he here, or where "here" even was. With him were others who also remembered little more than their own names. What they found when they came out of the underground was a world that was "just like a game." In order to survive, Haruhiro forms a party with others in the same situation as him, learns Skills, and takes his first steps forward into the world of Grimgar as a Trainee Volunteer Soldier. Not knowing what awaits him... This is a tale of adventure born from the ashes. (Source: J-Novel Club)
Hai to Gensou no Grimgar is a Japanese novel of 2,563,283 characters, with 31,943 unique words and 2,771 different kanji. Its difficulty rating on Jiten is hard, 3.4 out of 5. The full vocabulary list ranks all 31,943 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.