Flying Thunder God Kunai (Hiraishin Kunai) are custom-made kunai (tokuchū kunai) and signature tools of Minato Namikaze, who uses them in conjunction with his Space–Time Ninjutsu: the Flying Thunder God Technique. They differ from a standard kunai in that they have three blades instead of one and the handle (which is thicker than normal) serves as the marker for Minato's teleportation ability. Minato also said that these blades are a bit heavier than a normal kunai.[1] Their prongs also make them more deadly in melee fighting.