18 years ago on a stormy night, a young girl fled after saving someone due to a wrongful accusation. The rescued girl mistook her for a 'brother' and searched for eighteen years. An accidentally recorded cassette tape uncovered the truth. From lifesaving benefactors to side-by-side comrades, and then to blood-unrelated sisters, two women bound by fate became each other's most important people after taking back their stolen works and innocence.