The team investigated the "earth-bending" bandits, and found some soldiers who served a nearby daimyo. They had been victims of similar bandits, but there story was confusing and shamefilled. Still, the team visited the daimyo, and his chamberlain asked them to discreetly find the family Daisho, and return it dicreetly, no questions asked.
In their blundering, they found an abandoned ninja school underneath the castle, and it was infested with little peasants, an they had duped the 2nd son of the daimyo into the theft.
Regrettably all had to be killed, and the family historian, a mute, helped concoct a plausible story for the daimyo.