In Taylor Swift's “august,” the narrator is romantically attached to James.
The song presents an unnamed female character remembering a brief summer relationship with James. She hopes the connection might become something lasting, but James is already tied to Betty, and the relationship ultimately ends without the narrator truly having him.
Swift created the story as part of Folklore's “teenage love triangle.” “cardigan” is associated with Betty's perspective, “betty” gives James's perspective, and “august” presents the viewpoint of the other girl. The character is sometimes called Augustine by fans, although the song itself does not use that as a formal character name.
Another frequent mix-up involves Joe Alwyn's pseudonym William Bowery. That name is connected to songwriting credits on other Folklore material, not to the fictional boy in “august.” James is the character identified in the song's narrative.