In the 378th year of the Interstellar Era, the Human Federation was trapped in a double stranglehold between the Zerg Zerg and the Interstellar Pirate Alliance. The border defense lines were in defeat, the elite officers were wiped out, and the soldiers at the bottom were in danger. However, the top leaders of the Federation were secretly colluding with pirates and reselling military supplies, and the entire Federation was on the verge of destruction. Sun Kai is the most inconspicuous mecha maintenance soldier in the federal logistics. He is slightly fat, greedy for money and life, and his biggest dream is to open a tavern after completing his military service. However, he has top-notch mecha maintenance and transformation skills, as well as an instinctive sensitivity to terrain and numbers.
After the disastrous defeat of the Blackstone Defense Line, Sun Kai's physical resemblance to the legendary commander Lin Chen who died in the battle was urgently packaged as "Thunder Major" by the top management, and was sent to the most dangerous border, under the command of elite mecha commander Fang Ping. Fang Ping comes from a military family, she is cold-blooded and has excellent control over mechas. She was ostracized because she was unwilling to join the others and took over a remnant army that was on the verge of collapse. She saw through Sun Kai's flaws at a glance and tried to make things difficult for him many times, but was repeatedly resolved by his talent and cleverness when he was forced to show off. The two gradually fell in love during the tit-for-tat confrontation.
Sun Kai was forced to face the battlefield head-on, using modified tattered equipment and outrageous but miraculous deceitful tactics to lead the remaining soldiers to perform extraordinary feats and gradually awaken to their responsibility; Fang Ping also put aside her prejudice and aloofness and became his most solid backing. The two gradually turned from a superior and a subordinate who tested each other into a lover with the same heart. While fighting against the Zerg and pirates, they uncovered high-level corruption, the truth about Lin Chen's death in battle, and the secret connection between Sun Kai's missing grandfather and the Zerg. In the end, they worked together to defeat foreign enemies, eliminate internal traitors, protect human peace, and fulfill their mutual promises.
