: Kazune claims she is actually from "World Line 85," a reality where she and Koyomi are deeply in love. Key Themes

: After his parents' divorce, Koyomi chooses to live with his mother.

: Struggling with social awkwardness at a new prep school, Koyomi is suddenly approached by a classmate, Kazune Takigawa .

Set in a world where "Parallel Shifting"—the natural and frequent movement between slightly different realities—is a known scientific fact, the story follows .