Where to find music CDs?

I love Nishino Kana and Amuro Namie (singers) and since I'm coming to Japan, I would like to buy some of their discography. Do you know some CD shops in Osaka and Kyoto?

Any of the well know electronic shops. Second hand store like bookoff/cdoff. Heaps with a simple google search.

Tower Records is still a thing in Japan.

I buy far too many cd's every time I visit & I find Book Off or even better Book Off Super Bazaar to be the best, cheapest option. Locations are on this page https://www.bookoff.co.jp/inbound/kinki.html

Thank you everyone for your help. Can't wait to be in Japan!

Book Off is the one I wanted to mention. I found on in Kyoto (by the Sanjo subway station) which also sold secondhand CDs (maybe they all do!) and got a few things very cheap compared to the new Japanese proves.