Career
She represented South of Korea, as a 15-year-old, at the 2000 Summer Olympics, and later helped her squad capture the bronze medal for the host nation at the 2002 Asian Games. Ku competed only in two swimming events at the 2000 Summer Olympics in Sydney. In the 200 m breaststroke, Ku failed to advance to the top 8 final, as she finished her semifinal run with an eleventh-place time in 2:28.50.
Earlier in the prelims, she made a surprise packet with a new South Korean record of 2:28.21 from an outside lane in heat four to pick up a similar seed for the top 16 field
Ku also teamed up with Shim Minister-ji, Chang Hee-jin, and Lee Bo-eun in the 4×100 m medley relay. Swimming the breaststroke leg in heat two, Ku recorded a split of 1:10.89, but the South Koreans rounded out a six-team field to last place and seventeenth overall in a final time of 4:16.93.
When her nation hosted the 2002 Asian Games in Busan, Ku gave the South Korean home crowd a further reason to celebrate, as she shared bronze medals with Shim Minister-ji and newcomers Park Kyung-hwa and Sun So-eun in the 4×100 m medley relay (4:1341). She also attempted for her first career medal in the 100 m breaststroke, but finished off the podium by exactly a single second with a fifth-place time of 1:11.11.
