In the past month or so @SUNBO has got me onto pulling things from streaming sites. Prior to this, my goto was sukebei torrents but if the JAV was more than ~12 to 24-months old, I'd have a tough time getting something decently seeded. All the gems brought up here would largely go unexplored. Streaming sites like SupJav and JavGuru host older titles, and I prefer pull down the file for viewing. I use CocoCut and VideoDownloaderPro chrome extensions.
As an example, I wanted to get SHKD-957, based on a recommendation on Zenra.
www.zenra.net
Poorly seeded on sukebei, and usually that'd be where I'd give up. But SupJav has it.
I find that I have to switch back and forth between the server options beneath the playback controls. I find I have best luck with the "ST" or "SB" servers when they're available. Be sure to start playback of the video as well; seems CocuCut and VDP need playback to grab the link. You have to tolerate a p0rn ad onslaught, especially when you start the video streaming. A small price to pay IMO.

Once the video was playing, VDP was able to catch a downloadable link. Click the green box and start the download via Chrome. Bam.

Cocucut was also successful.

CocoCut will open a new tab to start the download. This isn't my preference but you can also get a downloadable link to use your browser instead if you click the "i".

Sometimes VDP will fail to give me any options; in those cases usually CocoCut will give you an option to download the "stream". Will post screengrabs of that scenario next time I run across it.
As an example, I wanted to get SHKD-957, based on a recommendation on Zenra.

ZENRA | FC’s Best JAV Videos of 2021: 10-1
Our last Best of 2021 and we end with my top videos of 2021.

Poorly seeded on sukebei, and usually that'd be where I'd give up. But SupJav has it.
I find that I have to switch back and forth between the server options beneath the playback controls. I find I have best luck with the "ST" or "SB" servers when they're available. Be sure to start playback of the video as well; seems CocuCut and VDP need playback to grab the link. You have to tolerate a p0rn ad onslaught, especially when you start the video streaming. A small price to pay IMO.

Once the video was playing, VDP was able to catch a downloadable link. Click the green box and start the download via Chrome. Bam.

Cocucut was also successful.

CocoCut will open a new tab to start the download. This isn't my preference but you can also get a downloadable link to use your browser instead if you click the "i".

Sometimes VDP will fail to give me any options; in those cases usually CocoCut will give you an option to download the "stream". Will post screengrabs of that scenario next time I run across it.