Sistema C.A.I. or Cambio Arma Istantaneo (Instantaneous Armament Change System) A complex puzzle of four storm boxes, four rain boxes, two lightning boxes, two sun boxes, and four cloud boxes. Only one who can utilize all five of these types of dying will flames can use this weapon to full effect. So far the only person capable of it is Gokudera. The main structure is a set of four circular bone shields that protect the user from attacks or can immobilize enemy box weapons. The storm flames of the bone rings are lightly covered in rain flames, which neutralize the initial part of the attack. Of the sixteen boxes, there are four skull rings for each of the other dying will flames, Uri, and Flame Arrow. The main method of attack of burst of dying will flame or missile projectiles that have two kinds of flames. The strength of this combination is the instantaneous change from one weapon to another, which give the weapon a high degree of unpredictability. The most powerful attack is the combination of Storm and Lightning flames into a concentrated burst called Flame Thunder. Gamma believes this to be an original invention of Innocenti, because of its flashiness.
Uri, the leopard cub is a component of Gokudera Hayato's Systema C.A.I.