History on Wikipedia, important name changes:
1) BMG Victor Inc. in Jan 1997 changed name to BMG JAPAN INC.
2) 1996 acquisition of Funhouse, then changed company name to BMG Funhouse effective Jul 1999-Oct 1 2005
3) Oct 1 2005 end of merger, reverted name back to BMG JAPAN INC.
BMG JAPAN INC. was kept separate from the (2004) creation of Sony BMG Music Entertainment, as Sony Music Entertainment (the American comapny) does not operate in Japan. In October 2008, Bertelsmann Music Group (BMG) itself became defunct, and Sony Music Entertainment (Japan) Inc. acquired BMG JAPAN INC.
BMG JAPAN INC. continued to use the BMG logo until June 2009 (when all domestic artists were rebranded under the Ariola label), and continued to use the BMG JAPAN INC. name until October 2009, when the domestic operations became Ariola Japan Inc. and the international operations were picked up by Sony Music Japan International Inc.