As the Gowa Consortium evaluates the failure of their experiment with Yushiro, the United Nations responds to what seems to be a weapons test in the renegade post-Soviet Republic of Belgistan. After a successful air attack, the allied ground forces suffer a startling defeat, leading the Japanese company to reveal the secret of the Tactical Armor systems. It seems these units may have been responsible for the U.N. defeat at the hands of the Belgistanians.
核査察を拒否した中央アジアの小国ベギルスタンに多国籍軍が派遣される。しかし、予想を超えたベギルスタン側の反撃に多国籍軍は苦戦。豪和家の三男清春は、ベギルスタン側に二足歩行兵器があると推測し、豪和家は特自のTAをベギルスタンに派遣しようと動き出す。