# Irodori-TTS v2 Offers Open Japanese Speech Synthesis

> The 500-million-parameter model from researcher Aratako provides a high-quality, single-speaker voice under a permissive MIT license.

Published by The Open Weights on Mar 23, 2026. Canonical: https://theopenweights.com/news/irodori-tts-500m-v2-twfp

## Key facts

- Company: Aratako
- Model: Irodori-TTS-500M v2
- Version: v2
- Category: Text → Speech
- Modalities: Text → Speech
- License: MIT (Open weights, commercial use allowed)
- Parameters: 500M
- Precision: FP32
- Weights size: 2 GB
- Languages: Japanese
- Significance: minor
- Published: 2026-03-23
- Last verified: 2026-06-17
- Hugging Face: https://huggingface.co/Aratako/Irodori-TTS-500M-v2
- Canonical URL: https://theopenweights.com/news/irodori-tts-500m-v2-twfp

Independent AI researcher Aratako has released the second version of Irodori-TTS, a 500-million-parameter text-to-speech model designed for the Japanese language. The project provides a capable and efficient tool for generating a female voice, filling a need for high-quality, open-source models in languages other than English.

The model is built on the VITS (Variational Inference with adversarial learning for end-to-end Text-to-Speech) architecture, a popular framework known for producing natural-sounding speech. It was trained on the JSUT dataset, a public Japanese speech corpus from a single female speaker. The full model is now [available on the Hugging Face Hub](https://huggingface.co/Aratako/Irodori-TTS-500M-v2) for community use.

By releasing Irodori-TTS under the permissive MIT license, Aratako enables developers and researchers to freely integrate Japanese speech synthesis into their applications or use it as a foundation for further research. While many advanced text-to-speech systems remain proprietary, this release underscores the vital role of independent contributors in building a more open and multilingual AI ecosystem.

## Get the model

- [Hugging Face](https://huggingface.co/Aratako/Irodori-TTS-500M-v2)

## Sources

- [Aratako/Irodori-TTS-500M-v2](https://huggingface.co/Aratako/Irodori-TTS-500M-v2) — Hugging Face, Mar 23, 2026

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Source: The Open Weights (https://theopenweights.com/). Aggregated and written by Claude, curated by humans. Cite as: "Irodori-TTS v2 Offers Open Japanese Speech Synthesis", The Open Weights, Mar 23, 2026, https://theopenweights.com/news/irodori-tts-500m-v2-twfp