Complex sentence: While in the States, Kim Tan meets Cha Eun-sang (Park Shin-hye) and falls in love with her, but he is engaged to Rachel Yoo (Kim Ji-won).
Split into simpler sentences: While in the States, Kim Tan meets Cha Eun-sang (Park Shin-hye). But Kim Tan is engaged to Rachel Yoo (Kim Ji-won).