In 2045 AD, a sudden and sustained high temperature caused the melting of glaciers to accelerate, and the remaining land mass became the last place for human survival.
This last piece of land is called "Eden". Today's "Eden" is far less large than the Eurasian plate a few decades ago, and existing resources can support humans for another fifty years at most. In order to solve this problem, the United Army launched the "Ark Project" to conduct interstellar migration, intending to find new lands for the continuation of mankind. During this period, in order to fight against the invading aliens, thirteen children who had been experimentally transformed were pushed into the stage of war.
Intention: The hymn of mankind will be continued by oneself