What Is Niconico? Japan's Video Site Where Comments Scroll Across the Screen

Niconico (ニコニコ動画, Niconico Douga) is a Japanese video service on which viewers' comments scroll across the picture as it plays. If the question is when it started, the answer is 12 December 2006, when Niwango released it as an experimental service; it moved to a beta test on 15 January 2007. The service carried on after its parent, Dwango, merged with KADOKAWA in 2014, and in June 2024 a cyberattack on the KADOKAWA Group that included ransomware took it largely offline for about two months.

Comments that run across the video

An INTERNET Watch article from January 2007 explained how Niconico worked. A comment typed while a video plays appears over it straight away. Each comment is saved against its point in the running time, so later viewers of the same video see earlier viewers' comments go by at the same moment.

Its start was unusual too. According to the same article, during the experimental phase from 12 December 2006 Niwango did not reveal that the service was its own, because it was a trial. Niconico grew out of Dwango's work on the next version of Packeradio, its audio and image streaming service for mobile phones, and at the time viewers could also use Niconico's player to comment on videos hosted on YouTube and AmebaVision. According to INTERNET Watch, the service marked its first anniversary on 12 December 2007, and on 13 November that year the operator had announced that registered IDs had passed 4 million.

The TV Tokyo programme write-up covers how Hiroyuki Nishimura opened Niconico in 2006. There he recalls that server and bandwidth costs ran high and that it took four to five years to turn a profit. Nishimura was also the man who opened the anonymous board 2channel in 1999.

Combining with KADOKAWA

According to ITmedia, Dwango and KADOKAWA announced on 14 May 2014 that they had agreed to combine. They set up a holding company, KADOKAWA DWANGO, on 1 October, with each becoming its wholly owned subsidiary. Dwango's chairman, Nobuo Kawakami, was to become chairman and KADOKAWA's Tatsuo Sato president. The two had formed a broad business partnership in 2010 and a capital alliance in 2011, and they gave as their aim building a content platform without equal in the world for the internet age.

Paying members fall away

Niconico's main source of revenue was its monthly paid premium membership. According to a Toyo Keizai Online article in May 2018, premium members reached a record 2.56 million in January–March 2016, held that level through September, and then fell by about 50,000 a quarter from October–December 2016. Over the latest year they had dropped by 360,000, from 2.43 million to 2.07 million, and the article pointed to the popularity of free services such as YouTube. At the launch event for a new version, Niconico (Ku), users mostly asked for better picture quality and loading speed rather than new features.

The 2024 cyberattack

On 8 June 2024 Niconico suddenly stopped working. According to KADOKAWA's notice of 5 August, several servers in the KADOKAWA Group became inaccessible that day, and analysis confirmed a large-scale cyberattack that included ransomware. The attack targeted the group of services centred on Niconico, and file servers dedicated to Dwango in the group's data centre were among those hit. According to GAME Watch, Dwango explained on 14 June that ransomware had made many servers in its private cloud unusable, that it had shut down all of them to stop the infection spreading, and that backups had also become inaccessible; restoring service would take at least a month.

At 15:00 that same day a stand-in, Niconico Douga (Re:Kari), went up. According to AV Watch, Niconico's developers proposed it themselves and built it in three days. It recreated the look of the 2006 Niconico Douga (Kari) with only the basics, viewing and commenting, and offered mostly popular videos from 2007 without an account, though only from within Japan to avoid overload.

According to GAME Watch, Dwango announced on 26 July that Niconico Douga and other services would return in a new version on 5 August. Niconico Community would not come back because the data and systems needed to restore it had been lost, and compensation for paid services was extended from June and July to include August.

On 5 August KADOKAWA published the results of its investigation, carried out with help from an outside security firm. Personal data of 254,241 people in total was confirmed to have leaked. It included personal data of some business partners such as creators, of all Dwango employees, and of students, graduates and parents connected with N Junior High School, N High School and S High School, along with corporate information such as contracts. KADOKAWA said no leak from Dwango of Niconico users' account details (login email addresses and passwords) or credit card data had been confirmed. It believes the root cause was the theft of employee account credentials through phishing or a similar attack, but said the route and method remained unknown.

The attackers are known from press reports. According to The Record (13 December 2024), a group calling itself BlackSuit claimed the attack and said it had taken about 1.5 TB of data. The same article relayed Kyodo News's report that KADOKAWA appeared to have paid a ransom of nearly US$3 million, based on emails the attackers sent to KADOKAWA executives and on cryptocurrency transaction records. KADOKAWA did not respond to The Record's requests for comment on the payment; according to the article, it had said in November that it expected an extraordinary loss of ¥2.3 billion from the cyberattack in the year to March 2025.

Lineage

Unlike YouTube, which spread at the same time, Niconico laid viewers' comments over the picture itself. The attack on the KADOKAWA Group became a case in which ransomware, which encrypts files and demands payment, brought down a major Japanese internet service. For the wider story, see the social media timeline.