The Brown Eyed Girls’ Ga In will make her surprise comeback through a remake version of old school R&B duo As One’s “For You Not to Know.” The single will be released as part of the 21st anniversary special album for the legendary producer, Yoon Il Sang.

According to reports, Ga In’s new single will be unveiled on March 21. It’s the fourth pair of singles made available for Yoon Il Sang’s special commemorative album, “I’m 21,” alongside No Brain’s “One Flew over the Cukoo’s Nest,” which is a remake version of Kim Gun Mo’s 1997 hit single.

“The songs released so far from Yoon Il Sang’s 21st anniversary album have been good, but the fourth pair of singles are tracks that fully spiced up Ga In and No Brain’s unique charms,” an official from Yoon Il Sang’s album said.

Meanwhile, “I’m 21” is a special album commemorating the 21st anniversary of Yoon Il Sang’s illustrative career. Other artists to have featured in the album include 10cm, Paul Potts, Super Junior K.R.Y., and JK Kim Dong Wook.

The MV below is As One’s original version of “For You Not to Know.” Enjoy the video!