How to Set Up a VTuber Pet in VTube Studio

ellyblerp
·
Aug 5, 2026

A VTuber pet lets your Live2D model react to your stream audio by lip syncing, moving, and responding to sounds through Blerp and VTube Studio. Follow the steps below to connect your pet and get it working on your stream.

What You Need

Before starting, make sure you have:

  • VTube Studio

  • OBS (or other streaming software)

  • A Blerp Unlimited subscription

  • Any Live2D model

Step 1: Load Your Pet Model in VTube Studio

Open VTube Studio and load the Live2D model you want to use as your pet.

This is the model that will receive lip-sync and movement data from Blerp.

Step 2: Enable the VTube Studio API

Blerp connects to VTube Studio through the Plugin API.

In VTube Studio:

  1. Open Settings

  2. Go to the Plugin Settings section

  3. Enable Start API

This allows Blerp to send lip-sync data to your pet.

Step 3: Enable Your VTuber Pet in Blerp

Open your Blerp Stream Dashboard.

Navigate to the VTuber Pet feature and enable your pet.

For your first setup:

  1. Enable Pet 1

  2. Confirm your pet is turned on

  3. Leave Custom Port disabled unless you changed the API port in VTube Studio

If you changed the VTube Studio API port, enable Custom Port in Blerp and enter the matching port number.

Blerp supports up to three VTuber pets at the same time. You can add additional pets after your first one is working.

Step 4: Choose When Your Pet Lip Syncs

Blerp gives you three options for when your pet should react.

All Audio

Your pet reacts to all stream audio, including:

  • TTS

  • Sound effects

  • Alerts

This is the recommended option for a single pet setup.

TTS Only

Your pet only lip syncs when text-to-speech plays.

Sound effects and other audio will not trigger movement.

Specific Voice

Choose a specific TTS voice for your pet.

This is useful when using multiple pets and assigning each pet its own voice.

Step 5: Connect Blerp to VTube Studio Through OBS

Open OBS and update your existing Blerp Browser Source.

  • Right-click your Blerp Browser Source

  • Select Properties

  • Add this to the end of the URL: ?vts=true

  • Click OK

VTube Studio should show a plugin permission request.

Click Allow to connect Blerp.

If the Plugin Request Does Not Appear

Try refreshing your Browser Source:

  1. Right-click your Blerp Browser Source

  2. Select Properties

  3. Click Refresh Cache of Current Page

If it still does not appear:

  • Restart OBS

  • Restart VTube Studio

To confirm the connection:

  1. Open VTube Studio

  2. Go to Plugin Config / Permissions

  3. Look for the Blerp VTS Plugin

If it appears in the list, your connection is successful.

Step 6: Map Your Pet's Lip Sync Parameters

After connecting, Blerp adds new parameters to VTube Studio.

The main parameter you need is:

Blerp Mouth Open

To set up lip syncing:

  1. Open your pet model settings in VTube Studio

  2. Find the parameter that controls mouth movement

  3. Assign Blerp Mouth Open as the input

Most models use a parameter like:

ParamMouthOpenY

The other Blerp parameters are optional and can add extra movement:

  • Blerp Head Bob

  • Blerp Head Tilt

  • Additional expressions

Step 7: Test Your VTuber Pet

Return to the Blerp Dashboard.

Click:

Send Test TTS

If everything is connected correctly, your pet should immediately begin lip syncing.

Remember:

  • Audio plays through the OBS Browser Source

  • VTube Studio does not output the test audio

If your pet's movements look jittery:

  1. Open the parameter settings in VTube Studio

  2. Increase the Smoothness value

Step 8: Add Your Pet Alongside Your VTuber Model

Your pet is currently loaded as the main VTube Studio model.

To use it as a companion:

  1. Open Item Settings (⭐ icon)

  2. Select Load Current Model as Live2D Item

  3. Save the item

  4. Switch back to your main VTuber model

Your pet will remain on screen as a Live2D item.

You can then:

  • Resize your pet

  • Move it around your scene

  • Position it beside your VTuber model

The Blerp lip-sync parameters will continue working while your pet is loaded as an item.

How to Add Multiple VTuber Pets

Blerp supports up to three pets at once.

To add another pet:

  1. Open the VTuber Pet settings in Blerp

  2. Enable Pet 2 or Pet 3

  3. Load the additional Live2D model

  4. Map the matching parameters

For additional pets, use the numbered parameters:

Pet 1

Blerp Mouth Open

Pet 2

Blerp Mouth Open_2

Pet 3

Blerp Mouth Open_3

The same naming system applies to the other movement parameters.

Each pet can also have its own activation trigger and voice assignment.

Using Other Live2D Items as Pets

Your stream pet does not need to be a full character model.

You can use Live2D items such as:

  • Bunny ears

  • Floating characters

  • Accessories

  • Mascots

Load the item into VTube Studio, map the Blerp parameters, and it can react to your stream audio.

Running Pets in a Separate VTube Studio Instance

You can also run your pets separately from your main VTuber model.

To do this:

  1. Open another VTube Studio instance

  2. Change the API port for the second instance

  3. Enter that same port in Blerp under Custom Port

This allows Blerp to connect to the correct VTube Studio window.

Troubleshooting

My pet is not lip syncing

Check that:

  • VTube Studio API is enabled

  • Blerp has plugin permissions

  • Your Browser Source URL includes ?vts=true

  • Blerp Mouth Open is mapped correctly

My pet is not moving after connecting

Try:

  • Refreshing the OBS Browser Source cache

  • Restarting OBS and VTube Studio

  • Checking the Blerp VTS Plugin permissions

My pet audio is not playing

Make sure you are checking your OBS Browser Source audio. The sound does not come directly from VTube Studio.

Watch the VTuber Pet Setup Tutorial

Prefer a visual walkthrough? Follow along with our step-by-step video tutorial to connect your Blerp VTuber Pet to VTube Studio, enable lip syncing, and configure your pet for your stream.

▶️ Watch the full tutorial here