She was featured on fellow DSP Media artist Sunha 's first album Fahrenheit in the song `` String '' ( 2008 ) In April 2009 , she sang a duet with former Noel member Kang Kyun-seong called `` Happy And '' .
In April 2009 , she sang a duet with former Noel member Kang Kyun-seong called `` Happy and '' .