[1] The Pink Panda released 3 singles and 3 albums from 2004 to 2008 before Koga left the band after their final concert at Shibuya O-West on November 15, 2008.

[4] In 2012, Koga and other members of Gacharic Spin joined with Light Bringer vocalist Fuki to create the band Doll$Boxx.

[6] In 2010, Atoss International released Koga's first bass instructional DVD titled Zettai Hajikeru!

[9] The promotional video featured Koga playing bass accompanied by Gacharic Spin's full lineup.

[10] In 2001, Koga performed a guest role as a school bully in the television drama Kids War 3.