Kotatsu v0.8.0

Summer

Natsumikan, the summer look
Kotatsu wears Natsumikan now: warm cream, indigo ink and a little mikan orange. New installs start in her; yours keeps whatever you chose, and she’s one click away in Settings → Appearance. The original lives on as Natsumikan Classic. Read more

A visual novel in your pocket
Set Messages to Sprites and a phone turns the chat into a stage: the backdrop, the speaker in the face that fits, and the reply in a textbox. Tap the words to turn the page, tap the name for edit, copy and the rest. History brings the whole conversation back. Read more

A page for every character
The Card Studio is a character page now, in chapters: who they are, how it begins, how they look, how they talk. Simple shows what matters, Advanced shows everything, and the opening appears exactly as the chat will show it. Read more

A place behind the stage
Give a chat a backdrop for the Sprite view: draw the place with Pictures, or upload your own. The Background chip over the chat has both. Read more

Kotatsu on Android
Kotatsu runs on Android phones as an app: the server, your characters and your chats live on the phone itself. Connect it with an API key, or a model running on your network; Claude Code and ChatGPT plans need a computer. Download the APK from the release page and install it. Read more

Also in this release

• Sprite sets come out truer to the character: a confident grin stays on the neutral face instead of following her into sadness, sad and angry faces can change the mouth, and a green-eyed character keeps her eyes when the background is cut.
• The bottom of a figure on the stage fades in softly instead of eating their boots.
• Send feedback (Settings → System → Help) opens a pre-filled GitHub issue. You see everything before it’s sent, and it never includes your chats, names or keys.
• On a phone, the keyboard sits under the composer, the bars step aside while you read, and a tap or a pull on the story puts the keyboard away. Landscape gets its story back.
• Settings on a phone opens on Close instead of the search keyboard, and its tab row shows that it scrolls.
• The Connection tab lists what you’ve actually set up first.
• Mikan-chan’s welcome tour wears Natsumikan too.
• Long Claude chats keep their prompt cache through more kinds of edits, and cache writes are counted on OpenAI-style connections.
• Kimi K3.1 Pro, Kimi K3 and K2.7 Code, DeepSeek Flash and GLM 5.3 FlashX work out of the box with their own keys. Kimi chats with thinking on stopped failing on the temperature slider, and K3 models get their full 1M context.
• Fixed: a tag with a background colour and no text colour is readable, New Entry in a lorebook scrolls to the new entry, and opening Kotatsu from a link with a query string no longer loads it twice.

Built from the private source repo at ca4e157e4 (kotatsu).

Install (Windows): download Install-Kotatsu.bat below and double-click it.
Install (Android 9+): on the phone, download Kotatsu-Android.apk below and open it; allow installs from your browser when Android asks.
Update an existing install: click the pill in the header, or run Update.bat.

Kotatsu v0.7.7

Sprites

Faces on the stage
Set Messages to Sprites in Settings → Appearance, and your cast stands beside the chat. Each finished reply picks the face that fits it. In a scene, whoever speaks steps forward. Read more

A whole set from one drawing
In the Card Studio, open Sprites and choose Generate. Pick the drawing you like best, and Kotatsu paints every expression from it, as a full body and as a bust. Your own ComfyUI does the drawing. Read more

Touch up the edges
A patch of background left behind? Touch-up’s wand clears it, and with Apply to matching sprites the fix lands on the whole set at once. Read more

Also in this release

• Long Claude chats cost a lot less: Kotatsu now caches your prompt with Claude, directly or through OpenRouter, and an Author’s Note or lorebook entry at any depth no longer breaks the cache. The cache chip under a reply says Healthy when it’s working.
• Local models work on the OpenAI-compatible connection: it no longer starts with Claude Code’s address and model in it, and replies no longer open with “assistant”. A local or home-network server you used last reconnects by itself.
• The preset dock finds the sections and pick-one sets in more presets: Deus Ex Machina, Pura’s Director and Megumin now open as tidy groups instead of one long list.
• On a phone, a message’s … menu keeps Translate on screen: its buttons wrap onto another row instead of running off the edge.
• A translator URL saved without http:// in front (LibreTranslate, Lingva, OneRingTranslator, DeepLX) works now, instead of failing with “Invalid URL”.
• Hover a prompt in the preset dock to read what its author says it does. Sola writes a note for most of hers.
• New sauces: Sola V3 · Flame and Sola · Kindling by Pyrxpia, and Freaky Frankenstein 5.4 by dptgreg. Already playing with Sola V2? Your copy stays where it is.
• The preset dock reads Sola V3’s sections and its pick-one sets, so which Sola, the point of view and the style are each one choice.
• A bundled sauce’s credit line has a Ko-fi link when its author has one. Tip the people who cook for you.
• The Chats list in the left rail is new. Pin the chats you return to, switch between Recent and Folders, and find each branch folded under the chat it came from.
• Folders come from chat names: “Arc - Part one” and “Arc - Part two” land together in Arc.
• Blue Hour has a new palette: a quieter blue-grey room with the accent standing apart from it, and solid main buttons that no longer look like a selected toggle.
• Gemini 4 Argon is in the Google model list, with its thinking levels and tool calls.
• Already have sprites? Upload them one by one, or import a pack (.zip), in the Card Studio’s Sprites tab.
• The Pictures sheet draws in two steps now: set up the scene, then Write scene. It opens on the model you used last.
• Generate says up front when ComfyUI isn’t answering, with a button to set it up.
• Claude Code is optional, and its notice now says so. Don’t show again turns it off.

Built from the private source repo at cd46e7175 (kotatsu).

Install (Windows): download Install-Kotatsu.bat below and double-click it.
Update an existing install: click the pill in the header, or run Update.bat.

Kotatsu v0.7.6

Sprites

Faces on the stage
Set Messages to Sprites in Settings → Appearance, and your cast stands beside the chat. Each finished reply picks the face that fits it. In a scene, whoever speaks steps forward. Read more

A whole set from one drawing
In the Card Studio, open Sprites and choose Generate. Pick the drawing you like best, and Kotatsu paints every expression from it, as a full body and as a bust. Your own ComfyUI does the drawing. Read more

Touch up the edges
A patch of background left behind? Touch-up’s wand clears it, and with Apply to matching sprites the fix lands on the whole set at once. Read more

Also in this release

• Local models work on the OpenAI-compatible connection: it no longer starts with Claude Code’s address and model in it, and replies no longer open with “assistant”. A local or home-network server you used last reconnects by itself.
• The preset dock finds the sections and pick-one sets in more presets: Deus Ex Machina, Pura’s Director and Megumin now open as tidy groups instead of one long list.
• On a phone, a message’s … menu keeps Translate on screen: its buttons wrap onto another row instead of running off the edge.
• A translator URL saved without http:// in front (LibreTranslate, Lingva, OneRingTranslator, DeepLX) works now, instead of failing with “Invalid URL”.
• Hover a prompt in the preset dock to read what its author says it does. Sola writes a note for most of hers.
• New sauces: Sola V3 · Flame and Sola · Kindling by Pyrxpia, and Freaky Frankenstein 5.4 by dptgreg. Already playing with Sola V2? Your copy stays where it is.
• The preset dock reads Sola V3’s sections and its pick-one sets, so which Sola, the point of view and the style are each one choice.
• A bundled sauce’s credit line has a Ko-fi link when its author has one. Tip the people who cook for you.
• The Chats list in the left rail is new. Pin the chats you return to, switch between Recent and Folders, and find each branch folded under the chat it came from.
• Folders come from chat names: “Arc - Part one” and “Arc - Part two” land together in Arc.
• Blue Hour has a new palette: a quieter blue-grey room with the accent standing apart from it, and solid main buttons that no longer look like a selected toggle.
• Gemini 4 Argon is in the Google model list, with its thinking levels and tool calls.
• Already have sprites? Upload them one by one, or import a pack (.zip), in the Card Studio’s Sprites tab.
• The Pictures sheet draws in two steps now: set up the scene, then Write scene. It opens on the model you used last.
• Generate says up front when ComfyUI isn’t answering, with a button to set it up.
• Claude Code is optional, and its notice now says so. Don’t show again turns it off.

Built from the private source repo at 8a135a3c9 (kotatsu).

Install (Windows): download Install-Kotatsu.bat below and double-click it.
Update an existing install: click the pill in the header, or run Update.bat.

Kotatsu v0.7.5

Sprites

Faces on the stage
Set Messages to Sprites in Settings → Appearance, and your cast stands beside the chat. Each finished reply picks the face that fits it. In a scene, whoever speaks steps forward. Read more

A whole set from one drawing
In the Card Studio, open Sprites and choose Generate. Pick the drawing you like best, and Kotatsu paints every expression from it, as a full body and as a bust. Your own ComfyUI does the drawing. Read more

Touch up the edges
A patch of background left behind? Touch-up’s wand clears it, and with Apply to matching sprites the fix lands on the whole set at once. Read more

Also in this release

• The preset dock finds the sections and pick-one sets in more presets: Deus Ex Machina, Pura’s Director and Megumin now open as tidy groups instead of one long list.
• On a phone, a message’s … menu keeps Translate on screen: its buttons wrap onto another row instead of running off the edge.
• A translator URL saved without http:// in front (LibreTranslate, Lingva, OneRingTranslator, DeepLX) works now, instead of failing with “Invalid URL”.
• Hover a prompt in the preset dock to read what its author says it does. Sola writes a note for most of hers.
• New sauces: Sola V3 · Flame and Sola · Kindling by Pyrxpia, and Freaky Frankenstein 5.4 by dptgreg. Already playing with Sola V2? Your copy stays where it is.
• The preset dock reads Sola V3’s sections and its pick-one sets, so which Sola, the point of view and the style are each one choice.
• A bundled sauce’s credit line has a Ko-fi link when its author has one. Tip the people who cook for you.
• The Chats list in the left rail is new. Pin the chats you return to, switch between Recent and Folders, and find each branch folded under the chat it came from.
• Folders come from chat names: “Arc - Part one” and “Arc - Part two” land together in Arc.
• Blue Hour has a new palette: a quieter blue-grey room with the accent standing apart from it, and solid main buttons that no longer look like a selected toggle.
• Gemini 4 Argon is in the Google model list, with its thinking levels and tool calls.
• Already have sprites? Upload them one by one, or import a pack (.zip), in the Card Studio’s Sprites tab.
• The Pictures sheet draws in two steps now: set up the scene, then Write scene. It opens on the model you used last.
• Generate says up front when ComfyUI isn’t answering, with a button to set it up.
• Claude Code is optional, and its notice now says so. Don’t show again turns it off.

Built from the private source repo at 61b0e4ae8 (kotatsu).

Install (Windows): download Install-Kotatsu.bat below and double-click it.
Update an existing install: click the pill in the header, or run Update.bat.

Kotatsu v0.7.4

Sprites

Faces on the stage
Set Messages to Sprites in Settings → Appearance, and your cast stands beside the chat. Each finished reply picks the face that fits it. In a scene, whoever speaks steps forward. Read more

A whole set from one drawing
In the Card Studio, open Sprites and choose Generate. Pick the drawing you like best, and Kotatsu paints every expression from it, as a full body and as a bust. Your own ComfyUI does the drawing. Read more

Touch up the edges
A patch of background left behind? Touch-up’s wand clears it, and with Apply to matching sprites the fix lands on the whole set at once. Read more

Also in this release

• On a phone, a message’s … menu keeps Translate on screen: its buttons wrap onto another row instead of running off the edge.
• A translator URL saved without http:// in front (LibreTranslate, Lingva, OneRingTranslator, DeepLX) works now, instead of failing with “Invalid URL”.
• Hover a prompt in the preset dock to read what its author says it does. Sola writes a note for most of hers.
• New sauces: Sola V3 · Flame and Sola · Kindling by Pyrxpia, and Freaky Frankenstein 5.4 by dptgreg. Already playing with Sola V2? Your copy stays where it is.
• The preset dock reads Sola V3’s sections and its pick-one sets, so which Sola, the point of view and the style are each one choice.
• A bundled sauce’s credit line has a Ko-fi link when its author has one. Tip the people who cook for you.
• The Chats list in the left rail is new. Pin the chats you return to, switch between Recent and Folders, and find each branch folded under the chat it came from.
• Folders come from chat names: “Arc - Part one” and “Arc - Part two” land together in Arc.
• Blue Hour has a new palette: a quieter blue-grey room with the accent standing apart from it, and solid main buttons that no longer look like a selected toggle.
• Gemini 4 Argon is in the Google model list, with its thinking levels and tool calls.
• Already have sprites? Upload them one by one, or import a pack (.zip), in the Card Studio’s Sprites tab.
• The Pictures sheet draws in two steps now: set up the scene, then Write scene. It opens on the model you used last.
• Generate says up front when ComfyUI isn’t answering, with a button to set it up.
• Claude Code is optional, and its notice now says so. Don’t show again turns it off.

Built from the private source repo at 34ebcb338 (kotatsu).

Install (Windows): download Install-Kotatsu.bat below and double-click it.
Update an existing install: click the pill in the header, or run Update.bat.

Kotatsu v0.7.3

Sprites

Faces on the stage
Set Messages to Sprites in Settings → Appearance, and your cast stands beside the chat. Each finished reply picks the face that fits it. In a scene, whoever speaks steps forward. Read more

A whole set from one drawing
In the Card Studio, open Sprites and choose Generate. Pick the drawing you like best, and Kotatsu paints every expression from it, as a full body and as a bust. Your own ComfyUI does the drawing. Read more

Touch up the edges
A patch of background left behind? Touch-up’s wand clears it, and with Apply to matching sprites the fix lands on the whole set at once. Read more

Also in this release

• Hover a prompt in the preset dock to read what its author says it does. Sola writes a note for most of hers.
• New sauces: Sola V3 · Flame and Sola · Kindling by Pyrxpia, and Freaky Frankenstein 5.4 by dptgreg. Already playing with Sola V2? Your copy stays where it is.
• The preset dock reads Sola V3’s sections and its pick-one sets, so which Sola, the point of view and the style are each one choice.
• A bundled sauce’s credit line has a Ko-fi link when its author has one. Tip the people who cook for you.
• The Chats list in the left rail is new. Pin the chats you return to, switch between Recent and Folders, and find each branch folded under the chat it came from.
• Folders come from chat names: “Arc - Part one” and “Arc - Part two” land together in Arc.
• Blue Hour has a new palette: a quieter blue-grey room with the accent standing apart from it, and solid main buttons that no longer look like a selected toggle.
• Gemini 4 Argon is in the Google model list, with its thinking levels and tool calls.
• Already have sprites? Upload them one by one, or import a pack (.zip), in the Card Studio’s Sprites tab.
• The Pictures sheet draws in two steps now: set up the scene, then Write scene. It opens on the model you used last.
• Generate says up front when ComfyUI isn’t answering, with a button to set it up.
• Claude Code is optional, and its notice now says so. Don’t show again turns it off.

Built from the private source repo at 0df74752d (kotatsu).

Install (Windows): download Install-Kotatsu.bat below and double-click it.
Update an existing install: click the pill in the header, or run Update.bat.

Kotatsu v0.7.2

Sprites

Faces on the stage
Set Messages to Sprites in Settings → Appearance, and your cast stands beside the chat. Each finished reply picks the face that fits it. In a scene, whoever speaks steps forward. Read more

A whole set from one drawing
In the Card Studio, open Sprites and choose Generate. Pick the drawing you like best, and Kotatsu paints every expression from it, as a full body and as a bust. Your own ComfyUI does the drawing. Read more

Touch up the edges
A patch of background left behind? Touch-up’s wand clears it, and with Apply to matching sprites the fix lands on the whole set at once. Read more

Also in this release

• New sauces: Sola V3 · Flame and Sola · Kindling by Pyrxpia, and Freaky Frankenstein 5.4 by dptgreg. Already playing with Sola V2? Your copy stays where it is.
• The preset dock reads Sola V3’s sections and its pick-one sets, so which Sola, the point of view and the style are each one choice.
• A bundled sauce’s credit line has a Ko-fi link when its author has one. Tip the people who cook for you.
• The Chats list in the left rail is new. Pin the chats you return to, switch between Recent and Folders, and find each branch folded under the chat it came from.
• Folders come from chat names: “Arc - Part one” and “Arc - Part two” land together in Arc.
• Blue Hour has a new palette: a quieter blue-grey room with the accent standing apart from it, and solid main buttons that no longer look like a selected toggle.
• Gemini 4 Argon is in the Google model list, with its thinking levels and tool calls.
• Already have sprites? Upload them one by one, or import a pack (.zip), in the Card Studio’s Sprites tab.
• The Pictures sheet draws in two steps now: set up the scene, then Write scene. It opens on the model you used last.
• Generate says up front when ComfyUI isn’t answering, with a button to set it up.
• Claude Code is optional, and its notice now says so. Don’t show again turns it off.

Built from the private source repo at 814e3d52e (kotatsu).

Install (Windows): download Install-Kotatsu.bat below and double-click it.
Update an existing install: click the pill in the header, or run Update.bat.

Kotatsu v0.7.1

Sprites

Faces on the stage
Set Messages to Sprites in Settings → Appearance, and your cast stands beside the chat. Each finished reply picks the face that fits it. In a scene, whoever speaks steps forward. Read more

A whole set from one drawing
In the Card Studio, open Sprites and choose Generate. Pick the drawing you like best, and Kotatsu paints every expression from it, as a full body and as a bust. Your own ComfyUI does the drawing. Read more

Touch up the edges
A patch of background left behind? Touch-up’s wand clears it, and with Apply to matching sprites the fix lands on the whole set at once. Read more

Also in this release

• The Chats list in the left rail is new. Pin the chats you return to, switch between Recent and Folders, and find each branch folded under the chat it came from.
• Folders come from chat names: “Arc - Part one” and “Arc - Part two” land together in Arc.
• Blue Hour has a new palette: a quieter blue-grey room with the accent standing apart from it, and solid main buttons that no longer look like a selected toggle.
• Gemini 4 Argon is in the Google model list, with its thinking levels and tool calls.
• Already have sprites? Upload them one by one, or import a pack (.zip), in the Card Studio’s Sprites tab.
• The Pictures sheet draws in two steps now: set up the scene, then Write scene. It opens on the model you used last.
• Generate says up front when ComfyUI isn’t answering, with a button to set it up.
• Claude Code is optional, and its notice now says so. Don’t show again turns it off.

Built from the private source repo at 4507b9877 (kotatsu).

Install (Windows): download Install-Kotatsu.bat below and double-click it.
Update an existing install: click the pill in the header, or run Update.bat.

Kotatsu v0.7.0

Sprites

Faces on the stage
Set Messages to Sprites in Settings → Appearance, and your cast stands beside the chat. Each finished reply picks the face that fits it. In a scene, whoever speaks steps forward. Read more

A whole set from one drawing
In the Card Studio, open Sprites and choose Generate. Pick the drawing you like best, and Kotatsu paints every expression from it, as a full body and as a bust. Your own ComfyUI does the drawing. Read more

Touch up the edges
A patch of background left behind? Touch-up’s wand clears it, and with Apply to matching sprites the fix lands on the whole set at once. Read more

Also in this release

• Already have sprites? Upload them one by one, or import a pack (.zip), in the Card Studio’s Sprites tab.
• The Pictures sheet draws in two steps now: set up the scene, then Write scene. It opens on the model you used last.
• Generate says up front when ComfyUI isn’t answering, with a button to set it up.
• Claude Code is optional, and its notice now says so. Don’t show again turns it off.

Built from the private source repo at a9642f010 (kotatsu).

Install (Windows): download Install-Kotatsu.bat below and double-click it.
Update an existing install: click the pill in the header, or run Update.bat.

Kotatsu v0.6.1

Docker

An official image
Kotatsu now has an official container image, ghcr.io/lumenastrum/kotatsu, for amd64 and arm64 (0.6.1, 0.6 and latest). Everything it keeps lives in one folder mounted at /config, it runs as a regular user, and it works with a read-only filesystem. docker/docker.md has the compose file, security and reverse-proxy notes, and backups. Thanks to @calmcacil for the detailed request (#1) and to @siestamode, whose Dockerfile this grew from.

Coming from the 0.6.0 Dockerfile? It used three volumes. docker.md has the few commands that move them into the one folder.

The notes below came with v0.6.0.

Pictures

Draw the moment
Choose the paintbrush on a message, or Draw a picture in the wand menu. The writer drafts a prompt from the scene; change what you like, then Draw. Mikan-chan paints while you wait. Read more

Your own ComfyUI
Point Settings → Pictures at your ComfyUI. The setup guide names any model that is missing, with a link to download it. Pick a model and preset in the sheet, and give a card its LoRAs. Read more

Also in v0.6.0

• No GPU? Pictures can also draw with your own OpenAI or Google AI Studio key, the one you added under Connection.
• The old Image Generation extension is gone. Your settings from it carry over to Pictures.
• Kotatsu runs in Docker: see docker/ in the repository. Thank you, @siestamode, for the first outside contribution.

Built from the private source repo at e794d5f7c (release/v0.6.1).

Install (Windows): download Install-Kotatsu.bat below and double-click it.
Update an existing install: click the pill in the header, or run Update.bat.