The Bone Loops are one of the Storm Boxes that make up Gokudera's Sistema C.A.I. They are multiple circles composed by small bone-like parts that expand themselves and float around once charged with Flames. The space between the loops is filled with a screen of Storm Flames. They mainly serve as shields, but can also be used to immobilize enemies by surrounding them like a prison. They can also be simultaneously charged with Flames of other attributes for compound effects, such as having an extra layer of Rain Flames that partially neutralize attacks with their Tranquility factor. The Bone Loops are currently part of the Storm Cambio Forma Version Vongola Gear.