1990s' dance group R.ef has returned. The group appeared on May 18th's airing of 'Yoo Hee Yeol's Sketchbook - Youth Night 2', and proved their still-growing skills and undying popularity.

'Youth Night 2' is the second '90s special aired after the success of the first in March. Other top stars from the 1990s who guested on the special include Shin Seung Hoon, Turbo's Kim Jong Kook, HaHa, Cool's Lee Jae Hoon and Kim Sung Soo, So Chan Hee, and Sung Jin Woo. miss A's Suzy also guest starred, filling in for Yuri of Cool.

With the exception of Park Chul Woo, members Lee Sung Wook and Sung Dae Hyun performed together as R.ef for the first time in 14 years, and pumped up the audience with their talented dance moves and vocals.

This performance marks the beginning of Lee Sung Wook and Sung Dae Hyun's comeback preparations. Apparently, the two are receiving many love calls from famous composers like Joo Young Hoon.

Source & Image: E Today via Nate