<human>:  Why does the main character, Zero, have a katana?
<bot>: The katana is a traditional Japanese sword. It’s a single-edged sword with a curved blade. The katana was originally developed in the 16th century as a weapon for the samurai class, who were the warriors of feudal Japan. The katana was the primary weapon of the samurai, and the blade was usually paired with a matching wakizashi.