Su-ji and U-ri

U-ri's Congenital Heart Condition (1x93)

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Na-young finally gathers enough clues about the situation to have leverage over Jin-tae, but Hyun-sung begins to suspect that she and Jin-tae might be hiding something from him. Doo-ri finds out that Do-young is Na-young's brother and breaks up with him, while Su-ji is left puzzled by how U-ri supposedly had a congenital heart condition.