Hanza is the leader of the Koga Ninja Team which is sent out to investigate the strange news that men were seen riding through the Shimota village area just before the plague hit. Hanza's eagerness persuades the Chamberlain to let him and his team investigate.
Although we don't get to see much of him, we can see that he is in fact a brave warrior as he steps in to defend Kagero against an all but invincible foe. Of all the ninja he is the one that seems to have cared the most about Kagero. One quick glance was all it took, but they both looked away...
Hanza is also seen later in the movie as one of Zakuro's walking dead bombs.