A small green gunpla, it is stored inside the Momokapool with its arms and legs retracted, resembling a ball. Momoka came up with this gimmick after seeing boxes within boxes. The Petitkapool pops out when the Momokapool's head opens, and can be used as an escape pod or as a Petit Mobile Suit for movement purposes. It can also be used to scratch enemy Gunpla during combat. Once the Petitkapool is ejected, the Momokapool turns inactive as Momoka's control is transferred to the small Gunpla. The Momokapool can be reactivated when the Petitkapool returns into its body. The black, white and pink version of Momokapool that appears later have a white and black colored Petitkapool hidden in its body.