Su-ji and U-ri

The Pieces Are Coming Together (1x86)

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Jin-tae visits Sun-young upon seeing U-ri's childhood toy while U-ri heads over to Ma-ri's home for dinner. After U-ri's visit, Na-young's sneaking suspicion grows, and Su-ji finds out that Hyun-sung had a brother. The next day, U-ri wakes up from a strange dream feeling sad and confused.