A traditional Japanese style, designed by the need to train soldiers and samurai in unarmed combat against armoured warriors when barefist striking wouldn't be effective. This system uses the weaknesses in body mechanics for join locks/breaks, throws and chokes. But keep in mind that it uses these methods because it assumes that striking is not an option.
Relationship to Krav Maga
Krav Maga takes some techniques from Jujitsu, joint locks, holds and thows are useful combat training in the military and police forces when it is necessary to restrain an opponent.