Voices of a Distant Star

In 2039, a human Mars exploration team discovered ruins of an alien civilization on the Tharsis Highlands. However, they were attacked by suddenly appearing life-forms and annihilated. To counter the threat posed by these aliens, named "Tarsians," the United Nations established the United Nations Space Army. In 2046, Mikako Nagamine, then in her third year of middle school, passed the selection to become a robot pilot for the UN Space Army. The following year, she was assigned to the Lictia Fleet to pursue the Tarsians. Departing Earth aboard the flagship Lictia, she left behind Noboru Terao, the person she loved. As the fleet chased traces of the Tarsians and moved further from Earth, the distance between them began to be measured in light-years, and the time required for their mobile phone emails to reach each other grew ever longer. Eventually, Mikako arrived at a planet in the Alpha Centauri system, located 8.7 light-years from Earth. There, she sent a text message to Noboru that would take 8.7 years to arrive. In the subsequent battle against the Tarsians, the UN forces were nearly wiped out, but Mikako survived.