Glossary for Kyojuro Rengoku

The pre-modern stratum of Japanese (Heian through late Edo) that no one speaks today but every educated Japanese reader recognises. Manga authors borrow from it to mark a character as old-school, theatrical, or sacred — Rengoku's 「よもやよもや」 is a clean example.

A cluster of grammatical particles, pronouns and verb endings (俺, ぞ, だぜ, うまい) that Japanese speakers — and especially manga writers — use to mark a line as 'spoken by a man,' independent of the speaker's actual gender.

The 15-year reign of Emperor Taishō (1912–1926). A brief, cosmopolitan window between the Meiji modernisation drive and the militarised Shōwa years that followed — the historical setting of Demon Slayer.

A Meiji-era beef hot-pot dish (the direct ancestor of sukiyaki) packaged as a railway-station bento. The dish Kyojuro Rengoku ravenously eats on the Mugen Train, three times exclaiming 「うまい！」.

One of the five direct branches of Sun Breathing (the original style). Practitioners regulate their breathing to push physical capability past human limits, then execute named forms styled after flame. Kyojuro Rengoku is the ninth-generation user.

A junior Demon Slayer formally adopted as a personal apprentice by a Hashira, training to inherit the Hashira's seat. Literally 'inheriting child' — closer to a martial-arts uchi-deshi than to a Western 'student.'

The top-ranked nine swordsmen of the Demon Slayer Corps. The word literally means 'pillar' or 'load-bearing column' — the structural members on which the entire Corps rests. Kyojuro Rengoku is the Flame Hashira (炎柱).

The signature sword carried by every Demon Slayer Corps swordsman. Forged from sun-steel mined on a single permanently-sunlit mountain, it is the only blade capable of decapitating a demon. Changes colour to reflect its wielder's breath style.

The steam train commandeered by the demon Enmu, on which Kyojuro Rengoku, Tanjiro, Zenitsu and Inosuke fight through the arc that bears its name. The location of Rengoku's death and the meal at which he says 「うまい！」三回.

The demon ranked Upper Moon Three (上弦の参) and the killer of Kyojuro Rengoku at the end of the Mugen Train arc. Obsessed with physical strength; refuses to fight women; offers to turn defeated worthy swordsmen into demons rather than kill them.