Kotoba Technologies
Founded 2023 Β· 19 employees on LinkedIn Β· 14 known investors
Kotoba builds a real-time voice AI speech model and simultaneous translation technology, with strong performance in East Asian languages for AI agents and voice interfaces. Its models support text-to-speech, speech-to-text, and speech-to-speech translation, and can run on-premise, on-cloud, or on-device.
Also known as Kotoba Β· Kotoba Technologies, Inc.
Founders & leadership
Kotoba Technologies was founded in 2023 by Jungo Kasai.
Investors Β· 14
Also in the syndicate Β· 10
Funding
SEC filings, press & company announcements$10M disclosed across 1 of 3 rounds Β· 2025β2026
- Undisclosed amountSeedJun 2026Source β
- $10MraisedJun 2026 Β· 2 sources
KindredVentures, SalesforceVC, Sony_Innov_Fund
Source β
Source: company announcements and press reports β follow each round's link for the claim.
Company profile
researched Aug 2026Kotoba Technologies is a voice AI company developing real-time speech generation, recognition and simultaneous translation technology. Its core model, Koto, is an end-to-end voice AI system built for ultra-low-latency real-time speech, covering text-to-speech and speech-to-text for AI agents and voice interfaces as well as speech-to-speech for simultaneous interpretation. The company states sub-50ms TTS latency, fast STT, and speech-to-speech translation at the pace of a professional simultaneous interpreter, with deployment available on-premise, in the cloud, or directly on-device for edge and embedded applications.
Alongside model licensing, Kotoba offers a consumer-facing mobile application that provides real-time simultaneous translation in both voice and text formats, built on the same underlying speech model. Earlier released models include Kotoba-Whisper, a Japanese automatic speech recognition model, and Kotoba-Speech, a text-to-speech and voice cloning model. The company also ships DOTSU, an iOS simultaneous interpretation app offering speech-to-text interpretation, which launched in March 2025.
The company positions its accuracy across Japanese, Korean and Chinese as its principal technical focus, and describes its team as researchers, engineers and builders working on generative AI for speech translation across applications, devices and AI systems.
Founding story
The company was founded in October 2023 by Dr. Hiroyuki "Nori" Kojima and Dr. Jungo Kasai to develop real-time speech-generation AI aimed at reducing language barriers.
Business model
Kotoba monetizes through licensing of its Koto voice AI models to developers and enterprises for AI agents and voice interfaces, and through a consumer mobile translation application. Models can be delivered on-premise, on-cloud or on-device, supporting embedded and edge integrations as well as hosted use.
Model licensing for enterprise and developer integrations plus a consumer-facing translation app.
Traction
The company has released Kotoba-Whisper and Kotoba-Speech models and the DOTSU iOS simultaneous interpretation app, which launched in March 2025, with global rollouts planned beginning August 2025 and additional expressive Japanese text-to-speech models planned. Its Koto model is used to power Japanese-language voice for Agentforce, and it has partnered with jig.jp on real-time AI interpretation for SABERA smart glasses.
Latest developments
Recent company announcements include a $10M seed funding announcement to expand real-time voice AI across East Asia, a partnership with jig.jp bringing real-time AI interpretation to SABERA smart glasses, an event with Kindred Ventures, and Koto powering Agentforce voice in Japanese.
βΈFull profile β market position, technology, go-to-market, geography, history
Market position
Kotoba positions itself as a frontier voice AI company focused on real-time speech and simultaneous translation with a specialization in East Asian languages, operating across Japan and the United States.
Kotoba emphasizes accuracy in East Asian languages β Japanese, Korean and Chinese β for translation, transcription and generation, combined with very low latency and flexible deployment options including fully on-device operation. Its products target true simultaneous interpretation rather than live transcription alone.
Technology
The company's Koto model is an end-to-end voice AI system covering text-to-speech, speech-to-text and speech-to-speech translation, with stated sub-50ms TTS latency and speech-to-speech translation described as operating at the speed of a professional simultaneous interpreter. It is designed for on-premise, cloud and on-device/edge deployment. Prior model releases include Kotoba-Whisper for Japanese automatic speech recognition and Kotoba-Speech for text-to-speech and voice cloning.
Go-to-market
The company sells through model licensing to businesses and device partners while distributing consumer mobile apps directly; it has also pursued device and platform partnerships, such as integration with jig.jp's SABERA smart glasses and powering Japanese-language voice for Agentforce.
Developers and enterprises building AI agents and voice interfaces that require Japanese and other East Asian language speech, hardware makers embedding on-device interpretation, and end users of its consumer translation apps.
Geography
Offices in the United States and Japan; the company is described as Seattle- and Tokyo-based, with a product focus on Japanese, Korean and Chinese language markets and stated plans for global expansion.
History
Founded in 2023, Kotoba developed optimized Japanese speech models including Kotoba-Whisper for ASR and Kotoba-Speech for TTS and voice cloning, moving from live transcription toward simultaneous interpretation. It launched the DOTSU iOS interpretation app in March 2025 and announced an $11.83 million Seed 2 round in June 2025 led by Globis Capital Partners and Boost Capital, with proceeds directed at hiring AI engineers, model development, commercialization and global expansion. Subsequent announcements cover its Koto model, a partnership with jig.jp for SABERA smart glasses, and Japanese-language voice for Agentforce.
Compiled by commissioned research from 8 cited public sources β announcements, filings, and press listed under research sources below.
Key figures
latest reportedCompany-reported or press-reported figures, each dated to when it was claimed β not independently audited.
Timeline Β· 5
launches, deals, and filingsKotoba announced that its Koto voice model powers Japanese-language voice for Agentforce over the phone.
$10M source β
Kotoba Technologies raised USD 11.83 million (JPY 1.7 billion) in a Seed 2 round led by Globis Capital Partners and Boost Capital, with participation from SIP Capital and U.S.-Japan angel investors. Funds are earmarked for hiring AI engineers, model development, commercialization and global expansion.
$11.8M source β
Kotoba launched DOTSU, an iOS app offering speech-to-text simultaneous interpretation.
Dated company events from announcements, filings, and press; legal rows summarize public dockets and regulator releases.
In the news
βΈResearch sources Β· 8
primary sources listed
- Kotoba Technologieskotoba.tech Β· web
8 public sources were cited for this profile; the first-party ones are listed here.
Frequently asked questions
- What does Kotoba Technologies do?
- Kotoba Technologies builds real-time voice AI models and simultaneous speech translation optimized for East Asian languages.
- Who founded Kotoba Technologies?
- Kotoba Technologies was founded by Jungo Kasai in 2023.
- Who are Kotoba Technologies's investors?
- Kotoba Technologies's investors include Globis Capital Partners, Kindred Ventures, SIP Global Partners, Sony Ventures Corporation.
- How much funding has Kotoba Technologies raised?
- Kotoba Technologies has disclosed $10M raised across 1 of its 3 known rounds.