On the January 20 airing of 'Singderella', Super Junior's Heechul revealed that he used to sing on the phone to win the heart of a girl. 

The idol further explained that it was during his trainee years and the song he sang the most over the phone was Byun Jin Seop's "Back To You Again". Heechul also revealed the reactions of his fellow SM trainees at the time, and said, "It was when we used to live in dorms, and Donghae would walk by and comment, 'What the hell is he doing'."

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On the other hand, Heechul revealed that TRAX's Jungmo helped him out by playing the guitar for him.