On the June 22nd broadcast of MBC’s ‘Dancing with the Stars 2‘ a mission called ‘My Story’ was given to the contestants in which they had to express the story about their lives through dancing.
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Hyoyeon danced the cha-cha this day and came out on top as the winner.

Source: http://www.allkpop.com/2012/06/hyoyeon-says-girls-generation-to-me-is-a-miracle