Cen Lingqiu, a veteran employee of the transmigration bookstore, accepted one last mission before retirement—to prevent the female lead from committing suicide. The female lead was beautiful but frail, crippled in both legs, and used by the male lead as a substitute for his "white moonlight" (ideal love), locked away in his mountainside manor and forbidden from seeing anyone. Cen Lingqiu, however, transmigrated into the body of the male lead's sister, a vicious cannon fodder character who constantly bullied the female lead, leaving the delicate heroine utterly miserable. The system informed the female lead...