- YⅡK · 1999
- Damn (umru Remix) - Single · 2016
- Unification · 2001
- Unification · 2001
- YⅡK Special Album · 1999
- YⅡK · 1999
- YⅡK Special Album · 2000
- Paradigm - Single · 2006
- Try Again · 2000
- Ad Infinitum (Japan Edition 2002) · 1999
- Try Again · 2000
- Ad Infinitum (Japan Edition 2002) · 1999
- Demos Collected 2.0 · 2000
Albums
- 2001
Music Videos
- 2001
- 2001
- 2001
Singles & EPs
Compilations
About Y2K
- ORIGIN
- South Korea
- FORMED
- April 24, 1999
- GENRE
- Rock