Raised suckling poison arrows among the sparring Iga ninja factions, Mumon is a carefree 16th-century mercenary. When the ninja council makes a power play to defeat the young Nobukatsu Oda struggling to step into his father’s warlord shoes as they expand rule across the country, Mumon jumps into the fray to satisfy his new bride Okuni’s demand that he make good on his promises of wealth. Yet Mumon soon finds what is worth fighting for beyond money or nation.