The main story develops its characters carefully, and is the shadow or "unusual" events of the protagonist's life. These stories feature the mercenary group Mithril, their mobile base/submarine, called the TDD-1 Tuatha De Danaan, giant humanoid powered suits called Arm Slaves, and the various missions to which Sousuke Sagara is assigned. A highlight of the series is a serious and semi-realistic view of humanoid robotic weapons on the battlefield. The Arm Slave has…