Octopus Extermination at Mysen Castle!

S1, A4: Hiro and Shin safely arrive at Mysen Castle{town?}, and end their escort of the peddlers. While sightseeing around the castle, they meet a girl named Yuna who is being chased by soldiers for stealing a treasure. Moved by her story of stealing the treasure to help her sick parents, Hiro and Shin volunteer to exterminate the Kraken, who possesses the same treasure and haunts the castle floodgates.