描述來自外星的不明生物「BETA」入侵地球後，人類已持續與他們進行了數十年的戰爭，並且陷入了滅亡的危機之中。因此人類開始團結起來，駕駛著「戰術步行戰鬥機」，開始與 BETA 對抗，試圖挽回那陷入絕望的命運。

The world is ruled by spirits, goblins, and all manner of strange creatures. Human beings are persecuted, to the very point of extinction. One day, a golem and a lone human girl meet.

This is a record of the pair, one a member of a ruined race, the other a watchman of the forest. It tells of their travels together and of the bond between father and daughter.