Miku Miku Online : An Online MMD-based Chat Program

Miku Miku Online is a networked virtual world environment that essentially acts as a chatroom. It was released in mid September and a demonstration video was uploaded to niconico. The software allows multiple online users to essentially participate in a virtual chat “world”, where players are represented by 3D avatars rendered from MikuMikuDance models. The programmers obtained permission to import a specific set of MMD models, and they must be downloaded separately from the program itself. There is a list of links to the models on the official webpage for easy access, though. The entire setup can be a bit confusing, so we’ve put together a small overview of how we got it working on our end.

Getting started

This guide assumes that you are running Windows Vista/7 with Japanese Locale for non-Unicode programs and have DirectX already installed. Windows XP may work with AppLocale.

To start, download the latest version of Miku Miku Online from the download page by clicking on the latest mmo-client, and if you plan to run your own server, also download the latest mmo-server. Extract the client to a known folder, and run the Client.exe to test if it works. If the client crashes on startup, you cannot run the latest version of MMO and will have to use version 3.3_67 in order to run it, however you will not be able to connect to any of the public servers listed on the MMO website. If the client does run, you will be prompted to enter an IP address to connect to. By default, the program launches its own server at localhost ( which allows you to locally play on your own computer and if you wish to connect to another server, enter in the IP address or hostname in the box and connect.

Upon connecting to the server, you are greeted with the UI of MMO.

Each element of the UI such as the chatbox (top-left), minimap (top right), edit box (bottom middle), and model selection (bottom right) are moveable as well as adjustable if you click on the gray circle on the bottom right hand corner of the box.


  • W: Walk Forwards
  • S: Walk Backwards
  • A,D: Turn right or left
  • Space: Jump
  • P: Take Screenshots
  • Enter: Chat
  • Click and Hold Mouse: Camera Movement

To change your nickname, press Enter until you see a cursor in the edit box, then type in “/nick Nickname” without the quotes and Nickname being the nick you want. To get a front view of the model, turn the camera up using the mouse until it flips over to the other side. Gamepads are also compatible. If you happen to get stuck, type in “/escape” in the edit box to reset your location. If you encounter an error that says “ReferenceError: * is not defined”, the coffee mug is enabled, and to get back to the chat, click on the button that says チャット. To change the current model, click on the model that you wish to switch to in the model selection box. The minimap shows other characters and yourself as red dots, and also lists the number of people logged in.

Adding Models

Due to the design of the program, each client connected to the server requires the same models in order to view all of the custom models properly. Newer PMX models such as TDA Miku Append will not work with MMO.
To install a new model, download the model from the model list and extract the contents to the “Resources\Models” folder. If the folder contains more than one model (ex. Lat Miku) run the game once to let it generate the configuration files and separate each model file into a separate folder. Refresh the Models folder to see the updated folders, and copy the texture image files from the model zip into each of the folders. You can also rename the folders in the Models folder to whatever you want. To change the in-game name of the model, you have to open up the “info.json” file in the model folder with a text editor that supports UTF8 (Notepad ++) and change the second line in the quotes to a name that you will be able to understand. If you do change the model name, other players connected to the same server will also have to rename the model to what you named it in order to view it, so it is best to leave it to default unless you give your models folder to each client.

Advanced Configuration

All of the graphics options are stored in the “config.json” file located in the main MMO directory. Open up the file in a text editor, and to adjust the screen resolution, change the “screen_width” and “screen_height” to your desired size. You can also enable fullscreen by changing “fullscreen” to “true”, and to enable anti-aliasing, change “antialias” to “true”. If you enable anti-aliasing, fonts will become blurry and hard to read. Ensure that there are commas at the end of every line in order for the configuration file to work properly.

English UI:
To change the Japanese in-game to English, files with the text will need to be edited. All of the files below need to be opened in a text editor.

Line 5: “name”: “チャット”, —> “name”: “Chat”,
Line 44: text: “[サーバーより] ” + msg.system, —> text: “[System Msg] ” + msg.system,
Line 74: text: player.name() + “さんがログインしました”, —> text: player.name() + ” has logged in”,
Line 86: text: player.name() + “さんがログアウトしました”, —> text: player.name() + ” has logged out”,

Various Tweaks:
Chat bubble timeout: In the cards\textchat\main.js file, change the “var BALLOON_EXPIRATION =” on line 13 to the desired length in ms (10000 is 10 seconds, default is 40000 or 40 seconds)
More to be added upon request.

Hosting your own server

To host your own server, you will need to download the separate mmo-server files, and extract them. In the config file located in the folder, you can change the server name, stage (map) name, user limit, and banned IP addresses (blocking_address_patterns). The receive_limit_1 sets the average bytes/sec that a user can send before it is ignored, and the receive_limit_2 sets how many byes/sec it will forcibly disconnect the user at (used for spam prevention). Once the server is all configured, to allow people not in your local network to connect, you have to forward both TCP and UDP port 39390. Then give other clients your public IP address and have them connect to it.

Version 3.3_67 on Non-Japanese Operating Systems

In order to get MMO to work on operating systems that do not support Japanese for non-unicode programs, you have to run an older version of MMO, and rename the model folders and model names to launch the game. In your resources/models folder, you will need to rename every folder that contains gibberish or Japanese to regular English, and go in each folder to check if there is a filename that contains weird characters or Japanese in them, and rename them. There may be a fix for this in the future, but until then, this is a way to test MMO on certain computers.

About: Pengy

40 thoughts on “Miku Miku Online : An Online MMD-based Chat Program”

    1. I’m pretty sure the english side is to lazy to do that. Heck we can’t even get our own english vocaloids to sound good so creating a server is a bit out of our league at the moment.

        1. …Uh, please read more closely. They said, “we can’t even get our own English Vocaloids to sound good”, implying he is aware of the existence of English Vocaloids. And Oliver isn’t the only one, so I’m not sure why you’re saying our own “Vocaloid” and not “Vocaloids”…

          1. I miss-read the paragraph, too. I guess there is a blonde in all of us.
            But hey, the Japanese Vocaloids are FAR better than the English ones, the English Vocaloid voices annoy me.

          2. Lol, really? You think that the engloids are the worst quality? I guess you really haven’t gotten to know the Kagamines fully?

          3. I like the English ones, although I may be the slightest bit biased considered I’m kinda crushing on Oliver despite obvious reasons why I shouldn’t ///0-0///

      1. you do realize that japanese vocaloids can sound terrible without proper tuning right? Its just that it is in another language so english speakers can’t tell
        Plus, making an english vocaloid is fucking hard. There’s a lot more harder to pronounce phenonoms than with Japanese vocaloids.

    2. i would totally host an english server… if i could figure out how. i can’t really find a place that describes how to well.

  1. scusate mikumiku online non è a pagamento vero?cè italiano ? sai io adoro miku hatsune e vorrei giocaRE DAMMI 1 DRITTA

  2. I’m so afraid it’ll turn out into a commercial online game which has a centralized server, its own biased terms and conditions etc >.<

  3. As of the latest update for MMO, PMX models are supported. Tested with Masisi’s Miku V3 and TDA’s Miku Append and it works.

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