There are at least two bands named Rib
Black/doom metal from Austria, featuring members of Kringa. Released the demo Phalleoliticum in 2012.
Rib (りぶ) is a relatively new utaite who started uploading in 2010. His first cover was "Marygold" which has 33K views as of May 2012. He gained popularity with his covers of Pierrot (178K views) and Babylon (272K views). His main breakout cover was of Envy Catwalk, which has over 1 million views as of July 18, 2012.
He has a powerful and slightly nasal yet smooth voice and can hit fairly high notes.