Biography
Mega Man is not an artist. The game's music was composed by C. Manami, Yuukichan's Papa. If this non-artist appears in your charts, do Last.fm and yourself a favour. Fix your tags by putting the actual artist name in the artist field. The easiest way is to use Picard.
But you may also refer to the actual artist Robert Bormann who also is known as Mega Man.
Biography text from Last.fm, available under CC BY-SA.