In 2012 when Nikkatsu celebrated their 100th year there were quite a lot of roman porno titles being released.
Studio 復刻シネマライブラリー (reprint cinema library) released a total of 100 movies on Made-On-Demand DVD-R discs. Only a couple of the movies had been available previously (on DVD that is, many had been released as VOD). The discs are region 2 locked, no English subtitles on these and the quality probably varies a lot but I doubt many look very good. I can’t say anything for certain about the quality as I have personally only seen one of these discs. That one is interlaced non-anamorphic 1.85:1, probably better than the VOD version and VHS release of the same movie but… Still much better than nothing I guess.
I’m not sure what these discs have to do with the company Tsutaya as for almost two years they were the only store to sell them (both online and offline in physical stores). But now the Japanese Amazon seems to have listed all of the discs for sale as well and they even deliver these internationally (which Tsutaya didn’t do)!