Ah, yes, 8-bit chiptune. It's music that is performed and composed by using retro game hardware like the Famicom and the Gameboy as instruments. Love it, great stuff.
And as far as Japanese indie chiptune record labels go, Vorc Records is right up there. Vorc was chiptune-centeric website originally launched way back in 2001, and the record label is an off-shoot of that dating from 2006.
Vorc Records [Official Site]