Hyouryuu Eiyuu: Echo the Cluster (Light Novel)

854 years since humanity reached out into space… They are now the most populous species in the galaxy. The frontier country of Tsukimurakumo and the Holy Albiono Empire are embroiled in a lasting war over the resources of different planets. Kumainu Akane, a second lieutenant of the Tsukimurakumo army, and Lilis, a soldier of the Holy Albiono Empire were stranded after receiving damage during battle. Their machines were half-destroyed and neither were operable nor able to transmit messages. There, the two of them entered a truce to try to find a way back to their space sector. Fortunately, they were not lacking food supplies and had plenty of materials to work with such that it might be possible to return if they manage to combine their machines…? But, the estimated time needed for repairs is forty days. Will Akane and Lilis be able to cooperate and return home alive!?