The Floating Castle

In the year 1590, powerful daimyo Hideyoshi Toyotomi nears his plan to unify all of Japan, but he comes across a floating fortress known as Oshi Castle. Nagachika Narita, in charge of defending the castle, must use his army of 500 men to combat Toyotomi Hideyoshi's army of 20,000.
~~ Adapted from the novel "Nobo no Shiro" (のぼうの城) by Wada Ryo (和田竜).