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 light novel, two music albums (The Sound of Dreams and No Tame No Waltz), and a 3D adaptation/reimagining of the original game. Over time, it became a general copyright included with official Yume Nikki merchandise alongside the standard "2004-2008 kikiyama" copyright. The project has also been stated to be fully endorsed by KIKIYAMA, the creator of Yume Nikki.
yumenikki.net
yumenikki.net was the main website for Project Yume Nikki and displayed news and announcements related to the project, such as product releases and community activities. 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.
On the left side of the website's pages was a navigation bar with several different tabs, each labeled with a different door from the original game's Nexus. The navigation tab's pages are as follows:
 What is Yume Nikki? |
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 creators' 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 |
A tab added later into the website's lifetime in December of 2013. This coincided with the release of the NASU minigame 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. However, the app has since been removed from app stores and is currently unplayable. |
 Manga Information |
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 updated to include interviews of Machigerita and Tomizawa Hitoshi for their opinions and experience with the manga and Yume Nikki as a whole. |
 Novel Information |
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, 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. |
 CD Information |
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 former 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 |
A page for physical merchandise made for the project. Some of the merchandise includes patches, rubber straps, badges, pins, shirts, and more. More products were eventually added to the website and this tab over time. A full list can be found on the Yume Nikki Merchandise page. |
 Latest News |
A news tab regarding updates to the website. This includes announcements, product information and re-releases, and website bug fixes, which were sorted by date. |
 What is Project Yume Nikki? |
A page showing a basic description of 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 as a deep-purple version of the Teleport Maze background and another of Madotsuki's Room. Advertisements showing where Project Yume Nikki products were sold, such as at manga/comic stores and events, were also put on the website.
Additionally, the website linked two Twitter accounts that were associated with Project Yume Nikki. The first, under the handle @proyume, simply Tweeted about new releases and events related to the project, which was not too different from the website's existing News tab. The second, under the handle @pr_yumenikki, acted as a public relations account that posted additional information about the project's products. Unlike the website, the two accounts are still able to be visited and viewed without the use of an archive tool, albeit they are both inactive.
Popularity Poll
The results of a character popularity poll were posted on yumenikki.net in October of 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 of most to least votes. Said page also states that the poll started on August 8th and ended on August 23rd. The characters by their ranking are listed in the table below in the order they were shown on the website:
| #1 Madotsuki |
#2 Seccom Masada-sensei |
#3 Monoko (Stoplight form) |
#4 KyuuKyuu-kun |
#5 Shitai-san |
#6 Poniko |
| #7 Mars-san |
#8 Monoe |
#9 Uboa |
#10 Mafurako |
#11 Kamakurako |
#12 Monoko (Normal) |
| #13 Yuki-onna |
#14 Toriningen |
#15 Tokuto-kun |
#16 Namekuji |
#17 Train Passengers |
#18 The Black Cat |
| #19 Eye People |
#20 KALIMBA |
#21 Ittan-momen |
#22 O-Man |
#23 NASU |
#24 Dave Spector |
| #25 Nekoin |
#26 Pirori |
#27 Medamaude |
#28 Takofuusen |
#29 Jellyfish |
#30 FC Demon |
| #31 Fleebie |
#32 Mall Shoppers |
#33 Eyeball World background |
#34 Henkei Shita |
#35 Dwarf |
#36 Neon Parrot |
| #37 Shield-Folk World background |
#38 Nopperabou Witches |
#39 Wheelies |
#40 Strober |
#41 Nopperabou Ghost |
#42 Buyo Buyo |
| #43 Shield-Folk |
#44 Mouth Monsters |
#45 Frog |
#46 Guillotine |
#47 Kimajo |
#48 Neon Creatures |
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 paler 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 merchandise 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 be viewed.
Strangely, on January 4th, 2017, the website temporarily changed into a short news page discussing papers and writing articles, though the website 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, off-topic articles starting in April and continuing throughout 2017. Articles from the aforementioned paper/writing change began to be linked in the Latest News section. 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 in the website's Navigation section 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. The site would not be restored to its Yume Nikki theme after this server error. In November 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 stripped away and was now dedicated to a Japanese online casino also known as "Yume Nikki".
On June 8th, 2024, a ransomware attack by the cybercrime group BlackSuit struck Kadokawa's databases, causing a data leak. Around this time, many of Kadokawa's websites were set as "under maintenance" in an attempt to tighten security, which included both the website for YUMENIKKI –DREAM DIARY– and yumenikki.net. As of August 2024, the website currently displays a maintenance message. It is unknown if the website will be restored at any point.
Due to these changes, the only way to currently view the original appearance of yumenikki.net is through Internet archive websites such as the Wayback Machine.
2018
Under Project Yume Nikki, several other events relating to Yume Nikki occurred in 2018, five years after the initial project started. Due to yumenikki.net becoming inactive in 2015, these announcements were not made on the website and rather appeared through other online publications.
On January 7th, the light novel that was 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, confirming that the project was still somewhat 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.
Fangamer Merchandise
Merchandise
In 2020, the company Fangamer, a distributor of video game-related merchandise, released a set of Yume Nikki-based merchandise which included shirts, a pin of Uboa, a stationery set, and a Madotsuki plushie. Though the Project Yume Nikki copyright was not displayed on the item's pages for the US website listing, it was on the JP website listing, confirming that the merchandise was related to the project. Additionally, Fangamer also released three other pieces of Yume Nikki merchandise in 2022 which included a poster, desk toy, and Poniko plushie with an Uboa zip-up cover.
GiGO Shibuya
With the opening of GiGO Shibuya on July 21st, 2023, a limited edition Fangamer collaboration sold several taiyaki (named "Gameryaki") and coasters depicting various indie game characters. Of the coasters were two Yume Nikki-themed coasters: one depicting Monoko with Stoplight Madotsuki and the other depicting Monoe with Knife Madotsuki and Dave Spector. The collaboration is set to end in late November of 2023.
Also in GiGO Shibuya, a permanent Fangamer shop was set up named “Fangamer Japan in GiGO”, which sells the same Yume Nikki-themed merchandise as on the Fangamer website. A mural within the store also depicts various characters related to Fangamer's various collaborations, one of the characters being Madotsuki.
On September 16th, new "Gamer Drinks" were sold alongside the taiyaki. Said drinks also depicted various characters like the taiyaki, one of which was themed after Monoko and Stoplight Madotsuki, being served with kiwi and strawberry as well as a topper depicting Stoplight Madotsuki and Monoko in her transformed state. A dedicated sticker for the Yume Nikki-themed drink also depicts a simple black, red, and green illustration of the White Desert. These drinks are also sold with the aforementioned themed coasters.
On February 22nd, new "Gamer Drinks" and coasters were revealed. Two new Yume Nikki coasters depicted Poniko alongside Madotsuki and Uboa and KyuuKyuu-kun alongside Madotsuki. One of the new drinks was also Yume Nikki-themed, themed after Poniko and being served with cola and lemon jelly, also featuring a topper depicting Poniko and Madotsuki.