The jitte is another traditional Japanese weapon used by the hinin caste. It was very similar to a truncheon or tonfa, with a hook at the end. Used primarily for self-defense, the hook was used to disarm a katana wielding opponent, but it could also be used offensively to deliver blunt thrusts or strikes, or perhaps to pin an opponent.

It was also known as a "sword-breaker" because of its used to catch, and perhaps break, the opponent's sword. A crude diagram of one variation is below. My apologies if this doesn't come out very well on your end.