The female protagonist married the captain and the male protagonist to repay her kindness. After three years of secret marriage and cold treatment, she learned that there had always been an unattainable white moonlight in her husband's heart, and that person turned out to be her half-sister. The female protagonist decided to set the male protagonist free, but the male protagonist didn't realize until they divorced that his wife, who had no presence at all, was actually the famous aerospace safety engineer he had been looking for for a long time...
