Lu Chen unexpectedly acquires a gift-return system. By giving items to high-scoring girls, he can obtain several to a hundred times resource returns. To earn treatment fees to save his ailing sister, he invests in multiple talented and high-quality girls, successively reaping huge resources and high-level martial arts. As his strength skyrockets, during a catacomb actual combat assessment, he encounters an alien army invasion. Ultimately, relying on the foundation accumulated by the system, he turns the tide and becomes a talented martial artist who guards Huaxia.