In 2800 AD, humanity expands its footprints into the vast interstellar space while constantly facing the threat of interstellar mutants. To protect human survival territory, the federation has successively established multiple colleges to continuously cultivate reserve forces for guarding the territory, with countless people following in succession to build a security defense line at the border. On Planet M417, which is listed as a remote star, a young girl, Jiang Lin, runs a small grocery store with her mother, originally planning to apply for a college specializing in mechanical engineering, become a mecha designer, and live a stable life. A sudden invasion by mutants shatters the peace, and Jiang Lin rescues the severely injured Shen Mingjun of Dawn in the torrential rain.