
One's story revolves around Kouhei Orihara, the main protagonist, who suspects that at some point his current life will change while living a peaceful daily routine. Due to this, he begins to seclude himself in the Eternal World, a world within his mind. The game's main recurring motif is a focus on the Eternal World, a mystical alternate space which is never clearly explained, and the details of which are unknown.
ONE ~Kagayaku Kisetsu e~ is a Japanese visual novel of 425,511 characters, with 11,183 unique words and 1,823 different kanji. Its difficulty rating on Jiten is average, 2.5 out of 5. The full vocabulary list ranks all 11,183 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.