First Arrest by Perfect Dark, the Latest P2P Client

Different language, different application. That is not an exclusive phenomenon for web services like Facebook against Japanese big 3. The most popular P2P file sharing software on Japanese web is not BitTorrent.

First, it was western WinMX follower Winny. When Winny network caused chaos on society by virus (which uploaded private and enterprise files under Windows’ “My Documents” from companies and government organizations) and arrests.

The development of Winny was stopped, and P2P users migrated to Share. After some allegations by uploading copyrighted movies on Share, Perfect Dark, which began at end of 2006 and boasts its higher anonymity, has been taking the position of the former two.

screenshot by a blogger shinn_asuka_impulse

On January 27th, the first person who distributed copyrighted animation films over Perfect Dark network was arrested in Saitama prefecture. [J]

From the beginning of this year 2010, downloading illegal contents became crime by revised copyright law. Until 2009, only uploading side was illegal. However, this accusation is not by this extended download, but by upload.

News: Winny developer found not guilty

Judge Ogura at Osaka High Court found Isamu Kaneko, a developer of Winny, not guilty today, reversing the guilty ruling of 1.5 million yen fine made by the lower court.

Winny is a popular P2P file sharing software in Japan. Kaneko developed Winny and released it on notorious 2channel forum on May 6th, 2002.

In 2004, the developer was arrested for abetting copyright infringement. Prosecutor’s office said that Kaneko has created Winny to proliferate copyright infringement to overthrow copyright system in Japan.

However, Osaka High Court concluded that the accused didn’t have a clear intent to proliferate copyright violation. Also the judge decided that he can’t condemn Kaneko for just knowing that copyright piracy is rampant in Winny network.

Disclosure: Shunichi Arai is a vocal supporter of Isamu Kaneko.

Japanese P2P Filesharing Network Being Attacked From Cloud

As same as other fields, for point-to-point(P2P) file sharing, there are Japanese counterpart of Kazaa/Limewire/Torrent. Once it was Winny, but after the developer of Winny was prosecuted for making a file sharing application which possibly leads copyrighted material distribution and the development ceased, the open source successor Share took the position of the most popular file sharing platform for Japanese speakers.

Today, on the gigantic bulletin board 2-channel(2chan)’s “Download Ita” [J] (download board), many reports by Share users are observed, their Share process had been accessed more than 20 requests simultaneously from servers on Amazon EC2 cloud, resulted in the process freeze.


someone’s Share’s screenshot (via 2ch)

On 2 channel, it is said that this flood of access paralyses Share network, many Share clients likely went down.

There are a lot of discussion threads are up on several different boards on 2chan (it is hard to keep those URLs, as 2ch thread stops after 1000 messages and then stored into archive servers, you have to seek the next thread manually), and users are sharing info such like blocking Amazon EC2 IP addresses, applying anti SYN-floot patch, etc. However, as not all file sharing users are computer experts, if this type of flooding access continues it is possible that the Share P2P network will be shrunk.

No attackers nor his/her intention remain unclear yet.

See Also:

Share – Wikipedia [J]

Winny trial goes High Court


Winny is the most popular P2P file-sharing software in Japan.

Isamu Kaneko [JP], the developer of Winny, was prosecuted by Kyoto Prosecutors Office. Kaneko was found guilty and fined 1.5 million yen ($15,000). Kaneko and the prosecuter both appealed to Osaka High Court.

4th January, 2009, Toshimitsu Dan [JP], a lawyer of the defendant, and supporters of the defendant had a meeting to share latest information about the trial. [1]

Brief summary of Winny trial:

5th June, 2002, the beta version of Winny was released in a 2channel forum. Winny gained much popularity in Japan as a file sharing software.

27th November, 2003, two Winny users were arrested by a high-tech crime squad of Kyoto Prefectural Police. They were prosecuted for an illegal uploading of copyrighted contents. They were found guilty and got a suspended jail sentence.

9th May 2004, Isamu Kaneko was arrested, and was prosecuted for abetment of copyright violation on 31th May. Kaneko was released on bail on June 1.

Right after the arrest, supporters of Isamu Kaneko formed a website ‘‘ and a defense fund for him. The fund has been received 16 million yen ($160,000) donations from many anonymous people.

13th December, 2006, Kyoto district court convicted Kaneko and fined 1.5 million yen ($15,000).


October 2005, Kaneko published a book called ‘The Technology of Winny’. It describes a P2P file sharing technology which is used in Winny. [2]

[Disclosure] I am taking a leading role in supporting Isamu Kaneko. I am a creator of and a chair of the League for Software Engineers.

1. 無印吉澤 – Winny裁判報告会に行ってきました [JP]
2. Winnyの技術, Isamu Kaneko, ASCII Publishing, 6th October, 2005 – [JP] [JP]

Q&A: What is the Japanese equivalent of [Western web service]?

Here is a list of where Japanese users usually go on the web when they want to connect with their friends, buy something or get information. I feature “made-in-Japan” sites and software only (well, almost), knowing that i.e. Google, Amazon and Firefox are highly popular in this country as well.

Some of these Japanese sites are also available in English. I linked to the English versions whenever possible and marked them with [ENG].

Note: This list is highly subjective. If you have other ideas, please let us know in the comment section.

I) General web services

What is the Japanese equivalent of Google?
Yahoo! Japan.

Wikipedia Japan.


Yahoo! Japan Photos.

Minna no Topics (Everyone’s topics).

No equivalent.

Twitter Japan.

Nico Nico Douga.

Hatena Bookmark. [ENG]

dooyoo (price comparison engine)?


No equivalent.

imdb (Internet Movie Database)?
Nihon Eiga Database (Japan Movie Database).

Wall Street Journal Online?
Nikkei Online. [ENG]

Yahoo! Japan Auctions.


2 channel (the original).
Mixi Music (registration required).


Second Life?
Meet me.

Yahoo! Answers?
Oshiete!goo and Yahoo! Chiebukuro.

II) Blogs

What is the Japanese equivalent of Techcrunch?
Asiajin. [ENG]….Joke, people!

the Huffington Post?
No equivalent.

Boing Boing?

Gizmodo Japan.

III) Web tools and software:

What is the Japanese equivalent of Gmail?
Yahoo! Japan Mail


the iTunes store?
iTunes Japan (Lismo for mobile downloads which accounted for 90% of all music downloads in 2007 in Japan).


Sleipnir [ENG] and Lunascape [ENG].

IV) Web Companies

What is the Japanese equivalent of Federated Media?
Agile Media Network. [ENG]

Sequoia Capital?
NGI Group. [ENG]

Cirius. [ENG]

In case you want to know more, please add a comment.