As a new reporter for a movie trade magazine, I quickly learned that every film has its genre — even ones that don't play by genre rules. The industry slices genre-straddling films into discrete categories: action, comedy, sci-fi, etc. Call it crude, but this system serves a purpose: If you're a buyer looking for horror specifically, you can safely ignore anything labeled otherwise.

Japanese cinema has had its own genre categories for more than a century, though the genre landscape has changed greatly over the decades.

In the silent era Charlie Chaplin was as big a superstar in Japan as he was everywhere else in the world, but the favorite genre of local fans was jidaigeki (period dramas). Set primarily in the Edo Period (1603-1868), jidaigeki encompassed a wide range of stories, though the most popular genre subset featured samurai sword action. Informally known as chanbara eiga (swordplay films), this subgenre served much same function as the cowboy movie did in Hollywood: a cheap formula product for the masses.