Ken Hirai - The Changing Same (Album)
Ken Hirai - Why (Album)
Ken Hirai - 歌バカ10th Anniversary Complete Single Collection '95 - '05 (Compilation)
Ken Hirai - 歌バカ10th Anniversary Complete Single Collection '95-'05 (Compilation)
Sony Music Monthly Sampler July 2000 (Compilation)
Ken Hirai - Why (Single)