Apps by Chrono Eternus ／ No. 1 · 日本語
Slides or stories.
Hand it over, and it speaks.
A Windows app that turns PowerPoint notes or a novel manuscript into narrated videos
Kataribe: Audiobook.AI Beta V1.04 (2026-10-13)
For Windows 11, from the Microsoft Store or as a code-signed installer. Voices need an ElevenLabs API key; scripts and images need Gemini (or OpenAI). No subscription: you pay each service only for what you use.
Two doors, one app
Only what you hand over differs. The workflow and the result are the same, and in both cases a person approves the script and checks the voice and pictures.
Presentation video (from PowerPoint)
Just pick a .pptx. Each slide becomes the picture, and the text in its speaker notes becomes the narration. For internal briefings, training, product introductions and lectures.
- Notes are read exactly as written. No AI rewrites your script
- Slides without notes: hand over the document the slides were made from and the AI writes the speech, in the tone you choose (bright and lively, calm and polite, and so on)
- Long notes are split at sentence boundaries automatically. Captions on or off, your choice
- The aspect ratio follows the slides. A 16:9 video ready for YouTube or internal sharing
Narrated novel (from a manuscript)
Chapters are detected in a .docx / .txt / .pdf manuscript and each becomes a narrated video. The AI drafts a script that fits the length you set, then prepares the voice and scene pictures.
- Set “6 minutes per chapter” and the script is drafted as faithful excerpts of the original
- A scene picture per cut, with places and times of day kept consistent
- Multi-actor: a voice per character (Pro)
- From vertical (9:16) shorts to landscape (16:9) long-form
Three steps to a video
| Presentation video | Narrated novel | |
|---|---|---|
| 1. Hand it over | Pick the .pptx. If some slides have no notes, add the source document too | Pick the manuscript (.docx / .txt / .pdf), a voice, the aspect ratio and a target length per chapter |
| 2. AI prepares, you decide | The notes become the script as they are; missing parts are written by the AI. Approve, generate the voice, listen and mark OK or NG | The AI drafts the script. Approve, generate voice and pictures, listen and look, mark OK or NG. Every retake changes something |
| 3. Build and publish | Captions, title card and BGM are assembled into an mp4 ready for YouTube or internal sharing | |
Eight things Kataribe does well
Straight from PowerPoint
Hand over the .pptx and you are done: slides become pictures, notes become the voice. Edit the deck and re-import; the script and audio carry over.
Speech written from the source document
No time to write notes? Give it the document the slides were made from and the AI writes a speech that fits each slide, in a tone of your choosing.
Human ears are the last gate
A person approves the script and checks every voice and picture. Compare candidate readings with the “reading experiment”. That is where publishable quality comes from.
Scripts that fit the length (novels)
The AI drafts a script that brings the chapter to the length you set, in cuts of 60 to 100 characters that are easy to listen to.
Scene pictures, generated (novels)
The AI paints a scene for every cut. Style and world are fixed per project; the same place stays the same set and the time of day stays consistent. Your own images work too.
A pronunciation dictionary that grows
Fix a reading once and it stays in the dictionary for the next chapter and the next deck. Company names, product names and proper nouns keep getting better.
Portrait, landscape, square; Japanese and English
9:16, 16:9 and 1:1. Japanese and English manuscripts; the app, manual and terms switch language too. Caption size and font are selectable.
Costs you can see, data that stays with you
An estimate before every generation (about $1.2 for a 6-minute chapter, measured). Manuscripts and output stay on your PC.
Good for
Internal briefings and training videos, product and service introductions, lectures and seminars, YouTube explainers, and novels, readings and audiobook-style content.
Free and Pro
| Free | Pro | |
|---|---|---|
| How to get it | Free download | Same app, enter a license key |
| Features | Everything needed for production, presentations and novels alike | + Multi-actor (a voice per character) |
| Scale | 3 min per video · 3 chapters per project · 5 finished videos per month | Unlimited (20 min per video) |
| Finished video | “Powered by Kataribe” watermark + 3-second closing card | No watermark, no closing card |
| Publishing | Free | Free |
| Commercial use | Not allowed | Allowed |
| Price | Free | 4,800 JPY (tax included), one-time. One key for up to 3 PCs; 1.x updates are free |
| Availability | On this page | Japan only for now (bank transfer, from the Japanese page). Other countries: coming with online payment |
Business presentation videos (briefings, promotion, training and the like) count as commercial use, so please use the Pro edition for them. Fees of external AI services (ElevenLabs, Gemini, OpenAI, etc.) are paid directly to those services in both editions. Commercial use also requires a paid ElevenLabs plan.
Download
Free edition, Beta V1.04
Released 2026-10-13 · Windows 11 · Free
The Microsoft Store is the recommended way to install. Updates arrive automatically, there is no download hold or “Windows protected your PC” prompt, and no administrator rights are needed.
On PCs that cannot use the Microsoft Store, download the installer directly (same app, same license key)
Kataribe_Beta_V1.04_Setup.exe, code-signed by RAY Inc. (株式会社RAY). Served from our GitHub releases page · SHA-256: a570181adb0458d13b4fa11cf6c5ac8bbfa1315f71ba1c1fefeb446dce17a702
Changelog (Japanese) · User’s Manual
If you download the installer directly
- Your browser may say the file “isn’t commonly downloaded” and leave it named “Unconfirmed ….crdownload”. A new release has few downloads yet; the file itself is fine. Open the downloads list (Ctrl + J in Edge) and choose “…” → “Keep” → “Keep anyway”
- If “Windows protected your PC” appears the first time you run Setup.exe, click “More info”, check that the publisher is “株式会社RAY” (RAY Inc.), then click “Run anyway”. If the publisher is different or shown as “Unknown publisher”, do not run it, and let us know with the form below
- Setup.exe, the bundled ffmpeg and the libraries are all signed, so it also runs on PCs with Windows 11 Smart App Control turned on. Installing over an earlier version updates it and keeps your API keys and projects. Uninstall from Windows Settings → Apps
Requirements and getting started
- Windows 11 (no administrator rights needed for either the Store or the installer edition). Python and ffmpeg are bundled.
- Presentation videos use PowerPoint on your PC to export the slides as images. Without PowerPoint, put PNGs exported elsewhere into the project folder and it works the same way.
- Required: an ElevenLabs API key (voice) and a Gemini or OpenAI API key (scripts, pictures and speech generation). Optional: Anthropic (script with Claude), HeyGen (avatar intro).
- Getting started: the User’s Manual. With your own PowerPoint deck, write the notes, pick the .pptx and your first video is done. The bundled sample “The Night Post Office” makes a narrated novel in about 10 minutes for roughly $0.30.
- This is a beta. Please report problems with “Report” in the app or the form below.
About Pro
Pro (no watermark, no scale limits, multi-actor, commercial use) is a one-time license at 4,800 JPY (tax included), entered into the same app as the Free edition. It is currently sold in Japan only, by bank transfer from the Japanese page. For customers outside Japan, an in-app purchase through the Microsoft Store is in preparation. If you would like to be notified when it is available, use the form below.
Terms of sale for Pro licenses
| Product | Kataribe: Audiobook.AI Pro license key (entered into the same app as the Free edition; one key covers up to 3 PCs owned by the purchaser) |
|---|---|
| Price | 4,800 JPY (tax included) per key, Japan only. Pricing for other countries will be announced when online payment is available |
| Payment | Bank transfer within Japan (transfer fees are borne by the customer), with the account details sent by e-mail after application. Online payment for other countries is in preparation |
| Payment deadline | Within 3 business days of application; applications unpaid after that may be cancelled |
| Delivery | The key is sent by e-mail on the business day the payment is confirmed |
| Returns and refunds | As a digital product, keys cannot be returned or refunded once sent. Please try the Free edition first. If a key cannot be used due to our fault, we will reissue it or refund |
| Updates | Updates within 1.x are free. The handling of the next major version (2.0 and later) will be announced at that time |
| Requirements | Windows 11. Voice and image generation need your own API keys (ElevenLabs, and Gemini or OpenAI); their fees are paid directly to those services |
| Seller | RAY Co., Ltd. (legal notice, Japanese) |
License conditions: Terms of Use.
FAQ
Can slides without notes be narrated?
Yes. Upload the document the slides were made from (.docx / .txt / .pdf) and the AI writes a speech for each slide without notes, matching that slide’s topic. Slides with notes keep their notes. You can edit the generated speech on the script page.
Is PowerPoint required? What about Google Slides or Keynote?
PowerPoint installed on the PC is used to turn the slides into images. Without it, export the slides as PNG elsewhere and put them in the project folder; everything else works the same. Export Google Slides or Keynote decks as .pptx first (the notes are exported with them).
Can I change the tone of the narration?
When the AI writes the speech from the source document you can specify a tone such as “bright and lively” or “calm and polite”. The voice itself is chosen from your ElevenLabs voices. Text written in the notes is read exactly as written.
Is it fully automatic?
No. A person approves the script and checks the voice and pictures; nothing is OK just because it was generated. These two gates are what make the result publishable.
Is there a monthly fee?
No. The app is either the Free edition or a one-time Pro license. External AI services are pay-as-you-go, billed directly by each service (about $1.2 for a 6-minute chapter, measured; presentations generate no pictures, so only the voice is billed).
Does my unpublished manuscript or internal deck leave my PC?
Everything you make is stored on your PC. Notes and narration text are sent to ElevenLabs to generate the voice, and the text needed for scripts, speech and pictures is sent to Gemini or the AI you chose. Please check those services’ terms.
Can mispronunciations be fixed?
Yes. Mark the cut NG and retake it: register the word in the pronunciation dictionary, rephrase the sentence, or compare candidate readings and adopt one. Adopted readings stay in the dictionary and apply from then on.
Does it work with English decks and manuscripts?
Yes. Set the language to English and the script, captions, chapter labels and narration are in English. The app itself can be switched to English as well.
With Pro, can I monetize any material?
Rights to the manuscript or deck are separate. Use material you own the rights to. The commercial terms of the external AI services (such as a paid ElevenLabs plan) also apply.
Does it run on a Mac?
No. Kataribe is Windows 11 only.
Bug reports and questions
CHRONO ETERNUS ／ Kataribe: Audiobook.AI Beta V1.04 ／ Terms of Use ／ 日本語
