I was all set for this to be an over-the-top trailer for a fake movie, along the lines of Cocaine Shark or Attack of the Giant Bubbles. There are two things you need to know before watching this trailer: 1. it's extremely gory and bloody, which fulfills the over-the-top part, but 2. Ninja vs. Shark is a real movie. The actors are well-known in Japan, and IMDb has a plot summary.
In the Edo period, at the remote village of Okitsu, the evil cult leader Koushirou uses ninjutsu to ensorcel sharks and forces them to attack local pearl divers so the cult can steal the pearls from their mangled corpses. Desperate for help, the village chief hires Kotaro Shiozaki, a guard at a nearby temple, but Kotaro soon finds his path blocked by lady ninja Kikuma, and a gigantic shark that doesn't seem like something from this world.
Besides ninjas and sharks, the movie has zombies and/or vampires. And tons of CGI blood. Ninja vs. Shark will open on April 14th in Japan. No release date has been set for the US. You'll learn more at the film's official site, if you can read Japanese. -via Geeks Are Sexy