Rio Audio offers a OEMed MP3 Player in Japan. The Rio Audio SU70 is most likely originally manufactured by Korean Median. It is the M-Cody MX-100 we reported about recently.

The Rio Audio SU70 comes in 256MB and 512MB configurations. The SU70 measures 84x34x18mm (funny, the original M-Cody measures 82.7x32.6x21mm). The new Rio plays MP3, WMA (DRM), ASF and WAV. Features include USB 2.0, FM-Tuner and 3D Sound and a high 35 hour battery life.
Seems Rio Audio Japan missed a player for their market that is why the went and OEMed one. Not sure if Rio will bring this player to US or Europe.
People are still waiting for the mysterious Rio Chroma. The recently announced Rio Carbon seems to do well.

More details on Rio Audio Japan Product Page (Japanese). (News Tip: Jason Kim, Thanks!).