Kyoukai

Kyoukai, romanized as kyōkai, is a Japanese noun meaning boundary, border, or limit. In English, it is commonly translated as boundary or frontier and is used to describe edges between physical spaces as well as thresholds between states, identities, or realms. The term appears in everyday language and in academic disciplines such as geography, philosophy, and cultural studies.

Etymology and sense: Kyoukai is formed from the kanji 境 (boundary) and 界 (world, boundary). The combination emphasizes a partition that can be crossed or transgressed, often implying potential change rather than a fixed separation. The nuance includes liminality—the intermediate space between two domains.

Usage in culture: In literature, film, and media, kyōkai is employed to evoke crossing between worlds, life and death, or human and supernatural realms. Works may use kyōkai in titles to signal thematic focus on thresholds. A notable example is Kyoukai no Kanata (Beyond the Boundary), a 2013 anime series adapted from a light novel, which centers on characters who inhabit and navigate between human and supernatural spheres.

See also: boundary, liminality, border.