>>4 >>5I'm not gonna accept this easy answer. They could perfectly use a torrent client that won't send anything to IPs outside of Japan, if that's their objective. And they don't have to run their own trackers if that's hard in Japan, trackerless torrents work.
I understand that they'd rather have stronger anonymity than torrents, but once again it makes no sense not to build upon existing networks and protocols.
All the Japanese internets feel like it's 1994 all over again, with their aversion to buying domains, their sites designed with vintage versions of stuff like IBM WebSphere Homepage Builder, and optimized for phones and dial-up rather than their 60Mb internet pipes, and as I said all the amateurish software reimplementing in incompatible ways stuff already done better in the rest of the world.
It makes no sense that a big player in hi-tech approaches computers just like some tiny African country would. There has to be a reason.