Project Yume Nikki

Project Yume Nikki (also formatted as Project YUMENIKKI) was a collaboration project that expanded upon the original Yume Nikki game, aiming to overall promote Yume Nikki. The project resulted in the creation of various pieces of merchandise, a manga, a vocaloid album, a light novel, and a 3D adaptation/reimagining of the original game.

yumenikki.net
yumenikki.net was the main website for Project Yume Nikki and displayed news and announcements related to the project. The website initially went up in February of 2013, starting with a countdown timer featuring an image of Nekoin and using a darkened image of the Nexus as a background. On March 1st, 2013, the countdown ended and the website revealed various aspects of Project Yume Nikki with a navigation update being implemented on the website the next day.

Navigation
The website's pages are as follows:
 * "What is Yume Nikki?", which is a page explaining the basics of the game as well as how to download and play Yume Nikki. It also states near the bottom of the page that products of Project Yume Nikki are based on other creator's interpretations of the game and the project has been fully endorsed by KIKIYAMA. It also clarifies that the names of most characters used in the project are fan-names, though permission was given by KIKIYAMA to use character fan-names for recognizability reasons.
 * "App Information", which was a tab added later into the website's lifetime on December 19th, 2013. This coincided with the released of the NASU minigame from Yume Nikki on iOS and Android devices as an app. The page for it details the game's instructions and also states the app has a new ranking system.
 * "Novel Information", which provides details on Yume Nikki: I Am Not in Your Dream, a light novel released for the project. The page specifically details the author, Akira Hajiri, and illustrator, Ako Arisaka. This page also links to the novel's page on freegamenovel.com, which features character concept art and a link to a promotional video.
 * "Manga Information", which provides details on the Yume Nikki manga. It also gives the manga's creators, writer Machigerita and artist Tomizawa Hitoshi, as well as a link to read the manga online in Japanese, English, and Spanish. The page was later update to include interviews of Machigerita and Tomizawa Hitoshi for their opinions and experience with the manga.
 * "Music Information", which gives information on the music releases for Project Yume Nikki This includes the vocaloid album "Yumenikki No Tame No Waltz" and a remix album "YUME NIKKI Soundtrack - The Sound of Dreams". The page was also originally able to have a user submit mailing information to receive the albums through a CD, as well as a tapestry depicting the album's cover. All six songs in the vocaloid album can be listened to here and the remix album can be listened to in full here.
 * "Goods Information", which shows the physical merchandise made for the project. Some of the merchandise includes patches, rubber straps, badges, pins, shirts, and more. More products were eventually added over time. A full list can be found on the Official Goods and Media page.
 * "Latest News", which was a news tab regarding updates to the website. This includes announcements, product information and re-releases, and website bug fixes.
 * "What is Project Yume Nikki?", a page showing a basic description for the project and the companies/groups participating in it. It was also possible to sign a form on the website in order to join the project if a company, person, or group wanted to contribute.

The website also went through different visual changes while it was active. These include tab changes or additions as well as new background images such one of Madotsuki's Room. Advertisements showing where Project Yume Nikki products were sold, such as at vocaloid conventions or manga/comic stores, were also put on the website.

Popularity Poll
The results of a character popularity poll were posted on yumenikki.net on October 1st, 2013, though no snapshot archives for the website showing a voting page are known. A new page was created for the website showing the ten most popular characters voted in the poll, as well as thirty-eight runner-up characters listed in order or most to least voites. Said page also states that the poll started on August 8th and ended on August 23rd. The characters by ranking are listed in the table below by the order they were shown on the website: Interestingly, Monoko is split into two different characters. One vote depicts her when the Stoplight effect is used and another vote depicts her as she usually looks. The Pirori also use their appearance in the Sewers for their vote icon instead of their more common appearance used in the Barracks Settlement and Docks.

Aftermath and Repossession
After most of the pieces resulting from Project Yume Nikki had been released, the website remained largely inactive starting in the latter half of 2015. However, all of the pages were still able to viewed.

Strangely, on January 4th, 2017, the website temporarily transformed into a short news page discussing paper and writing articles, though the website was quickly reverted back to its Yume Nikki theme the next day. However, the Latest News tab at the bottom of the home page became completely blank and began to list odd, seemingly off-topic articles starting in April and contined throughout 2017. Articles from the aforementioned paper/writing change were linked in the Latest News section that were claimed to be made on April 1st and 8th of 2015, though no such articles were actually made at these times as shown through snapshot archives of the website during April 2015. Alongside these off-topic articles, another title appeared to advertise an upcoming online casino, which would foreshadow what ultimately became of yumenikki.net. Also by this time, all of the side tabs mentioned in the Navigation section of this article were removed (with the exception of the Latest News tabs, which now listed the various off-topic articles).

On December 19th, the home page was once again restored and the off-topic articles were all removed, though the Latest News tab in the side navigation was still left alone. Beginning at the start of 2018, the website began to fluctuate between what it had displayed in its Latest News section. The website either displayed no news at all or off-topic posts. If the latter of the two appeared, it now listed casino and slot machine ads in Russian.

On December 5th, 2019, the website experienced a server error and only displayed "database connection establishment error" on the screen in Japanese alongside no other features. In November of 2020, the website had completely changed to show a new background alongside white text claiming "Yumenikki.net SOMETHING IS HAPPENING!" In January of 2021, the website had everything Yume Nikki-related to it stripped away, and the website was now dedicated to a Japanese online casino also known as "Yume Nikki". This is the website's current appearance.

2018
Under Project Yume Nikki, several other events relating to Yume Nikki occurred in 2018, five years after the initial project started.

On January 7th, the light novel that originally released in 2013, Yume Nikki: I Am Not in Your Dream, was translated and published in English by Amber Tamosaitis. Two days later, v0.10a of the original Yume Nikki game was released on Steam by AGM Playism and Kadokawa. On the same day, the website for YUMENIKKI –DREAM DIARY– went up with a countdown timer ending on January 25th, revealing the game to the public and showing it was under the Project Yume Nikki copyright, showing that the project was somewhat still ongoing. YUMENIKKI –DREAM DIARY– would later release on February 23rd and version 2.0 of the game would release nearly two months later on May 24th.