Japan owes a lot to the samurai warlords who unified the country in the late 16th century, but these “great men” of history were really no better than yakuza bosses, willing to betray or behead anyone in their quest for power. Such is the lesson imparted by “Kubi,” Takeshi Kitano’s blood-drenched and breathtakingly cynical period epic.

Revisiting one of the most well-trodden eras in Japan’s past, the filmmaker dishes up a savage riposte to the sanitized versions of history presented by NHK’s Sunday night taiga dramas. Nobility is in short supply here, but there’s sodomy, butchery and too many decapitations to count.

Working from a 30-year-old screenplay, Kitano offers a heterodox account of the 1582 Honnoji Incident, in which warlord Oda Nobunaga (Ryo Kase) was killed in a rebellion organized by one of his generals, Akechi Mitsuhide (Hidetoshi Nishijima). The latter’s motives remain a subject of debate among historians, but “Kubi” posits a love triangle involving Nobunaga, Mitsuhide and another retainer, Araki Murashige (Kenichi Endo).