Su-ji and U-ri

Repeated Misfortune (1x59)

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U-ri and Sun-young realise Na-young is Su-ji's sister and Yoon-ja's daughter. Therefore, Sun-young wants to reveal the truth behind the videos of Su-ji and Na-young. Meanwhile, Yoon-ja barges into Na-young's apartment as she has nowhere to go after being kicked out of Jang-soo's house. Then she finds out Na-young is secretly dating Hyun-sung, hiding the fact that she is Su-ji's sister.