Mezue ahịrịokwu na-esonụ: Afọ anọ ka e mesịrị, Choi ruru eru maka ihe omume igwu mmiri abụọ na 2012 Summer Olympics na London site na imebi oge ntinye FINA A-ọkọlọtọ nke 2:13.00 (200 m onye medley) na 2:08.81 (200 m butterfly) site na FINA World Championships na Shanghai, China. Na 200 m onye medley, Choi kwụsịrị okpomọkụ anọ na nke isii site na 0.19 nke abụọ n'azụ Great Britain Sophie Allen, na-agbadata oge Olympic ya na 2:14.91. O tinyere nke iri abụọ na anọ na ọkụ ọkụ, ma ghara ịga n'ihu na ọkara ikpeazu. N'adịghị ka asọmpi Olympics ya ndị gara aga, Choi debara aha ya nke iri nke kachasị ọsọ nke 2:08.45 na
200 m butterfly iji chekwaa ọnọdụ ya na ọkara ikpeazu n'ụtụtụ ụtụtụ. Choi enweghị ike iru eru maka ikpeazu, ebe ọ kwụsịrị ịgba ọsọ nke ọkara ikpeazu na oge nke atọ kachasị nwayọ nke 2:08.32.