That's my friend's store in Japan. 100% legit. He flew out here to the Bay Area a few times to buy vinyl records in bulk from me. He actually travels to different US cities every few months to hit up record stores/collectors/artists and buys a shit load of music to send back to Japan. There might be a few official rereleases on there because sometimes he works out deals with some artists to repress their rare albums. About 5 years ago I went with him to buy stuff from City Hall Records and Rap Bay and he cleaned them out.
That dude HATES bootlegs WITH A PASSION. I asked him about the bootleggers in Japan and he got hella pissed. He said that bootleggers fuck up the music business and that it also affects his store. He said he would murder all the bootleggers in Japan if he could lol
Oh yeah..for the rare cd's that are cheap, those might be official rereleases from the actual artist. Or they can be OG copies he got a good deal on. For an example...one time he bought a box of OG Gangsta Rhyme Posse cd's from Vallejo Street Show for $10 a piece. He only sold them for $25 in Japan back when they were selling for $40-$50 on eBay.