Historically, katana were one of the traditionally made Japanese swords that were used by the samurai of feudal Japan. However, Japan's ancient warriors also plied less glamorous, lesser-known and therefore possibly more interesting weaponry.
Implements like the jutte and kusurigama allowed users to defend and combat the katana. Fans, smoking pipes and other weapons disguised as everyday items meant one had to be wary at all times. Other weapons, like rocket launchers, seem more fit for manga than actual battlefields.