
Some time in the past, the gods of the four seasons, spring, summer, autumn, and winter, shared their powers with chosen humans. Those who manifested these powers were called the "Agents of the Four Seasons," and they became the avatars of the seasons themselves, in other words, living incarnations of the gods. "Thy name is 'Autumn,' the one who comes after Summer." It is the middle of spring, in the 21st year of the Reimei era. Shugatsuki Natsuko, the Agent of Autumn in Yamato, was enjoying the season with her guard dog Hanagiri, her maid Makazu Miyohi, and her personal assistant Shirahagi Konoyo. And then there was Natsuko's Guardian and first love, Azaami Ryuubi. Their harmonious days are suddenly disrupted due to a diplomatic incident. The name of the country is "Hashikuni," it is a foreign land from across the sea, far from Yamato. Conspiracies loom, as the demands from Hashikuni put the Agent of Autumn and her followers in an unprecedented predicament....... (Source: Dengeki Bunko, translated)
Shunkashuutou Daikousha: Aki no Mai is a Japanese novel of 381,217 characters, with 12,481 unique words and 2,119 different kanji. Its difficulty rating on Jiten is hard, 3.3 out of 5. The full vocabulary list ranks all 12,481 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.