This is only tangentailly related to imageboards, but do you by any chance know anything about history of japanese peer-to-peer networks or where to find some reading material in japanese (excluding the /download/ board of course)? Although I realize Japanese people are not very eager to speak about such things under their current copyright situation which pains me greatly as too many files shared back in the day are either completely gone or just sitting there on some old hard drive never to be shared again.
I've been a long time user of these since 2008 but I'm interested in the WinMX era which I completely missed.