Owls' Castle (1999)

As great military commander Nobunaga Oda consolidates his power across Japan, one of his actions is to wipe out a clan of assassins, killing every man, woman and child he found in the village. Years later, one survivor has hired a young, skilled assassin to avenge his friends and family. His mission: to sneak into the most heavily guarded castle in Japan, and eliminate the supreme ruler.