ˌeɪtʃˌɛsjˈuː ænd kˈuːz ɹᵻlˈeɪʃənʃˌɪp dˈeɪts bˈæk tʊ ˈɔːɡəst nˈaɪntiːnhˈʌndɹɪd nˈaɪnti sˈɛvən wɛn ʃiː fˈɜːst sˈɔː kˈuː pɚfˈɔːɹmɪŋ ˌɔn stˈeɪdʒ wˌaɪl ɪnðɪ ˈɔːdiəns fɚɹə kˈɑːnsɚt baɪ tˌaɪwənˈiːz sˈɪŋɚ tˈɑːɹsi sˈuː.
Hsu and Koo's relationship dates back to August 1997 when she first saw Koo performing on stage while in the audience for a concert by Taiwanese singer Tarcy Su.