Sakana AI, a Tokyo startup founded in 2023 by ex-Google and ex-Stability AI researchers, has raised $379M and added Citi as a strategic investor in February 2026 to support global expansion. Its products are Fugu (model orchestration), Marlin (deep-research agent), and Namazu (Japanese LLMs), alongside a new RSI Lab launched in 2026.
Sakana AI is a Tokyo-based AI startup founded in 2023, now valued near $2.65 billion after raising $379M total. Citi became a strategic investor in February 2026 to help Sakana expand into North American and European financial services. In 2026 Sakana also opened a dedicated Recursive Self-Improvement (RSI) Lab studying AI systems that improve themselves with less compute.
Founded: 2023 · HQ: Tokyo, Japan · Team: 150-200 · CEO: David Ha · Funding: $379M total raised across seed, Series A ($214M, 2024), and Series B ($135M, Nov 2025). Investors: Lux Capital, Khosla Ventures, MUFG, NEA, In-Q-Tel, Nvidia, Google, Salesforce Ventures. Citi and Mitsubishi Electric made corporate strategic investments in 2026. · Valuation: $2.65B (Series B, Nov 2025)
About Sakana AI
Sakana AI was founded in Tokyo, Japan in July 2023 by David Ha, Llion Jones, and Ren Ito. David Ha served as Research Director at Google Brain and later as Head of Research at Stability AI before co-founding Sakana. Llion Jones co-authored the 2017 paper "Attention Is All You Need" while at Google, the paper that introduced the Transformer architecture now central to nearly every major language model. Ren Ito spent years as a Japanese diplomat, then served as Executive Officer at Mercari from 2015, and was COO of Stability AI in the UK before joining the founding team. The three founded Sakana on the thesis that frontier AI performance can be achieved through model orchestration and nature-inspired learning rather than brute-force scale.
Sakana AI's product lineup as of 2026 includes three offerings. Sakana Fugu (launched June 22, 2026) is a multi-agent orchestration system exposed as a single OpenAI-compatible API: you send a request to one endpoint and Fugu decides whether to answer directly or route the query to a coordinated pool of frontier language models. It comes in two tiers: Fugu (low-latency, everyday tasks) and Fugu Ultra (1 million-token context, $5 per million input tokens and $30 per million output tokens, built for complex multi-step problems). On SWE-Bench Pro, Fugu Ultra scores 73.7%, ahead of GPT-5.5 at 58.6% and Gemini 3.1 Pro at 54.2%.
Sakana Marlin, launched June 15, 2026, is an autonomous deep-research agent that works for up to eight hours on a single strategic brief and delivers reports of up to 100 pages with slides. Marlin is built on AB-MCTS (Adaptive Branching Monte Carlo Tree Search), a NeurIPS 2025 Spotlight result, and on The AI Scientist framework published in Nature. Pricing is 100 credits per run or monthly plans starting at roughly $1,000. The third product line, Namazu, is Sakana's family of Japanese-language LLMs including TinySwallow-1.5B, a compact model for Japanese text tasks.
Sakana AI raised $30 million in its seed round from Lux Capital and Khosla Ventures. In 2024 the company raised approximately $214 million (roughly 30 billion yen) in its Series A at a $1.5 billion valuation, with participants including Mitsubishi UFJ Financial Group, SMBC, Mizuho, Itochu, KDDI, Nomura, and Nvidia. In November 2025, Sakana closed a $135 million (20 billion yen) Series B round at a $2.65 billion post-money valuation; new investors included Factorial Funds, Macquarie Capital, Santander Group via Mouro Capital, and In-Q-Tel (the CIA's venture arm), joining returning investors Khosla Ventures, NEA, Lux Capital, plus Salesforce Ventures, Google, and Datadog. Citi announced a strategic investment on February 24, 2026, its first in a Japanese company, made through Citi's Markets Strategic Investments unit and intended to help Sakana export its models into North American and European financial services. Mitsubishi Electric made an additional corporate minority investment in March 2026, tied to its Serendie digital platform. Total funding across all rounds is approximately $379 million.
Sakana AI earns revenue from Fugu subscription plans at $20/month (Standard), $100/month (Pro), and $200/month (Max), as well as pay-as-you-go API pricing. The company's primary enterprise targets are Japan's finance, consulting, manufacturing, and government sectors. Marlin's closed beta in April 2026 ran with approximately 300 professionals from finance and consulting, validating demand before the general release. Public ARR estimates suggest roughly $30 million as of 2025, though Sakana has not officially confirmed a revenue figure.
David Ha serves as CEO, Llion Jones as CTO, and Ren Ito as Chairman. The team has grown to approximately 150-200 employees as of mid-2026, all based in Tokyo. Sakana published The AI Scientist in Nature and presented AB-MCTS as a NeurIPS 2025 Spotlight paper. The company also introduced the Darwin Godel Machine (a self-rewriting AI system) and the TRINITY and Conductor frameworks (multi-agent coordination methods grounding the Fugu architecture), both presented at ICLR 2026.
Sakana AI's stated mission is to develop AI based on nature-inspired intelligence: evolution, collective intelligence, and sparsity. The research agenda distinguishes Sakana from labs focused purely on scaling: rather than training ever-larger single models, Sakana studies how populations of smaller models can collaborate to solve problems that exceed any individual model's capability. In June 2026 the company formalized this direction with a dedicated Recursive Self-Improvement (RSI) Lab, which opened in Tokyo in August 2026 to research AI systems that can improve their own methods, code, and architecture using less compute rather than more, building on the earlier Darwin Godel Machine work. This approach also addresses a practical concern: Japan-based enterprises face uncertainty about long-term access to potentially export-controlled US frontier models, and Fugu's swappable model pool is designed so that any specific model can be removed or replaced without changing the API interface.
Sakana's primary competitors in the orchestration and Japanese LLM spaces include OpenAI (dominant globally but without Japan-specific models), Anthropic (strong on safety and enterprise, no Japan focus), and Preferred Networks (a Tokyo-based AI lab building Japanese industrial AI). Sakana beats all three on Japan-language model quality and on sovereign AI positioning for Japanese enterprises. Where Sakana is weakest: it has no consumer product comparable to ChatGPT or Claude.ai, and its orchestration layer depends on third-party frontier model APIs, so changes to OpenAI or Anthropic API access could affect Fugu's model pool.
Mission
Develop AI inspired by nature: evolution, collective intelligence, and sparsity, building sovereign AI technologies that capture Japanese language and culture.
Products
- Sakana Fugu (Orchestration model API): https://sakana.ai/fugu/
- Sakana Fugu Ultra (High-capacity orchestration model): https://sakana.ai/fugu/
- Sakana Marlin (Autonomous deep-research agent): https://sakana.ai/blog/
- Namazu LLMs (Japanese-language foundation models): https://sakana.ai
Sakana AI Models on HokAI
Links
Frequently Asked Questions
What is Sakana AI and what do they build?
Sakana AI is a Tokyo-based AI startup founded in July 2023 that builds foundation models and AI products for Japanese and global enterprise markets. Its flagship product is Sakana Fugu, an orchestration model that routes queries across a pool of frontier language models through a single OpenAI-compatible API. Sakana also offers Marlin, an autonomous deep-research agent, and Namazu, a family of Japanese-language LLMs. In 2026 the company also opened a dedicated Recursive Self-Improvement (RSI) Lab researching AI systems that can improve their own methods and code with less compute.
How much funding has Sakana AI raised, and who are its investors?
Sakana AI has raised approximately $379 million across a seed round, a $214 million Series A (2024, $1.5 billion valuation), and a $135 million Series B (November 2025, $2.65 billion valuation). Series B investors include Khosla Ventures, Lux Capital, NEA, Salesforce Ventures, Google, Datadog, and In-Q-Tel. Mitsubishi Electric made a corporate minority investment in March 2026, and Citi announced a strategic investment on February 24, 2026, its first in a Japanese company, intended to help Sakana expand its models into North American and European financial services.
What products does Sakana AI make?
Sakana AI sells three main products. Sakana Fugu, launched June 22, 2026, is a multi-agent orchestration API available in a standard tier and a 1-million-token Fugu Ultra tier priced at $5 per million input tokens and $30 per million output tokens. Sakana Marlin, launched June 15, 2026, is a B2B research agent that works for up to eight hours on a brief and produces reports of up to 100 pages. Namazu is Sakana's family of Japanese-language LLMs, including the compact TinySwallow-1.5B model.
What is Sakana AI's mission and research focus?
Sakana AI's mission is to build AI inspired by nature: evolution, collective intelligence, and sparsity, rather than scaling a single massive model. Published research includes The AI Scientist in Nature, the Darwin Godel Machine self-rewriting AI system, and the AB-MCTS method presented as a NeurIPS 2025 Spotlight paper. In 2026 the company formalized this direction further with a dedicated RSI Lab, announced in June 2026 and opened in Tokyo in August 2026, focused specifically on recursive self-improvement research.
Who are Sakana AI's main competitors?
Sakana AI competes in multi-model orchestration, Japanese-language LLMs, and autonomous research agents. On orchestration, OpenAI and Anthropic are the closest global reference points, though neither offers a dedicated orchestration-layer product; Fugu Ultra scores 73.7% on SWE-Bench Pro versus GPT-5.5's 58.6%. On Japanese-language AI, Preferred Networks is the most prominent Tokyo-based competitor. Sakana's clearest advantage is its Japan-sovereign positioning, since Fugu is designed to work without dependency on any single US export-controlled model.
Top Alternatives
- OpenAI: Pick Sakana AI if you want sovereign Japan-focused LLMs and model orchestration without locking into one frontier provider.
- Anthropic: Pick Sakana AI if your enterprise needs Japanese-language coverage or export-control-resilient model routing.
- Mistral AI: Pick Sakana AI if you need multi-model orchestration and Japanese market positioning rather than an open-weights European model.