3X3 Eyes is a Japanese animation (anime) that centers on a main character named Yakumo, whose father once discovered a race of demons still in existence, known as the Sanjiyans, who appear normal, but have the ability to pop a third eye in the middle of their foreheads which gives them great power. Yakumo discovers this when he meets Pai, the last remaining demon, who requires his help recovering a sacred Sanjiyan artifact that has been stolen. Yakumo becomes a Wu - a servant to the demons - and is unable to be killed. This anime is somewhat violent and graphic, as Yakumo is frequently killed, often in ways from which you would think he would never recover. The story of 3X3 Eyes can be difficult to follow for those unfamiliar with Eastern religions, as it is based on Hindu mythology.
