Perfect Dark

"Perfect Dark (パーフェクトダーク) is a peer-to-peer file-sharing (P2P) application from Japan designed for use with Microsoft Windows."
- Wikipedia English

In short, it's your best way to acquire obscure Japanese stuff, such as DLSite files, various doujin media, audio files0 and other obscure Japanese lewd entertainment.

0 Except for new releases, since new voice works seem to be uploaded into Perfect Dark rarely these days (there's still plenty of older ones though). Check Baidu instead.

System requirements:

1 Perfect Dark as a P2P system distributes files between its users. This cache is called unity, and the minimum you'll be able to limit it to is 40 GB.
2 As an example, my maximum upload speed is barely 100 KB/sec, and the software works fine for me.

Install instructions

Generally you don't need to worry about getting the latest version, since the program updates itself automatically. The latest version at the moment of writing this is 1.22, available here: Settings screen

Searching and downloading

Your main interface you'll be using is the search tab. Type a search word in the upper left white box and click add. Perfect Dark will now begin searching for any files with the specified text. Searching may be slow immediately after installing, because you don't have a decent sized cache built yet. You can still download regardless.

Search screen

Example search words to use:

3 All uploads don't necessarily have DLsite numbers, so search by name too to be sure.

Occasionally Perfect Dark may notify you about your complete list growing too big without any reviews. In that case go to the complete tab, select a bunch of files and review them from the right click context menu. Right click again and choose clear reviewed item. I'm not sure how the grading works to be honest.

Don't expect gigabit download or upload speeds. Usually you'll be seeing 100-300 KB/sec download speeds. I'm running one instance of PD on a server with 100MB-1GB connections and it still doesn't use much bandwidth.

Linux, Wine and Servers

Perfect Dark works fine on Linux under Wine. Some things to remember: