Disk Union Showa Kayo-Kan
Time Out says
There are several branches of Disk Union in Shinjuku, but the Showa Kayo Store is unique in that it specialises in popular Japanese music from the Showa period (1926-1989). Selling used records, CDs and books, the store covers a wide range of genres including enka (traditional Japanese pop ballads) and Japanese idols’ pop tunes.
Shinjuku Mitsumine Bldg B1F, 3-28-4 Shinjuku, Shinjuku-ku