SIDE6 was immersed in a peaceful and peaceful atmosphere, which was far from the battlefield, there was almost no war, and there were not many Union troops stationed here, which did not please the young Aru, for he was a military fan and longed to see the fierce battle scene. One day when Aru was communicating with his friends, there was an uproar in the colony, which was caused by a conflict between Jean's small reconnaissance unit and the Union. Soon after, a wounded Zack skimmed over Aru and crashed on the forest lawn not far from him. Barney, the shot-down Jean recruit, traded his badge for Aru's camera magnetic card, which recorded Aru's MS assembly from a federal factory. In addition, there is the appearance of Chris, a red-haired neighbor of the Aru family, who moved here from the earth a few days ago. The intelligence obtained by Barney attracted the attention of the Jean army, who immediately formed an assault team to carry out the mission of sabotage. So Barney's team, relying on the chaos of a small battle, sneaked into SIDE6 again. In the cosmic colony, Barney met Aru again. Aru, a teenager who wants to be a MS driver, volunteered to be Ji Entu.