Sakana AI made its name by taking other people’s AI models and making them better at being Japanese. Now the Tokyo startup will build domestic AI models from scratch.
From remixing to recording originals
Until now, Sakana AI’s playbook has rested on two techniques. The first is post-training, which means taking an existing foundation model and refining it for specific tasks and audiences.
The second is something the company calls evolutionary model merging. Think of it as selective breeding for software: combine traits from different models, keep what works, and discard the rest.
The approach has been sold on efficiency and cultural alignment. Rather than spending heavily to train a giant model from zero, Sakana adapted what already existed and tuned it for Japanese language, values, and use cases.
That strategy set Sakana apart from peers who chose to build AI frameworks from the ground up. The new plan puts the company closer to that camp, at least for its domestic models.
Sakana has pitched itself as a hedge against reliance on foreign models, particularly in sensitive sectors like finance and defense.
A fast-growing company with deep backing
Sakana AI was founded in Tokyo in 2023 by three former Google researchers: David Ha, Llion Jones, and Ren Ito.
As of mid-2026, the company employed an estimated 157 people.
In November 2025, Sakana raised ¥20 billion, about $135 million, in a Series B round at a post-money valuation of $2.65 billion. Japanese institutions and global investors backed that round. It came after a Series A that raised about $214 million at a $1.5 billion valuation.
The product lineup has expanded alongside the funding. The Namazu series is the company’s family of models tailored to Japanese applications. Fugu is an orchestration platform that coordinates multiple AI agents working on a single task. Marlin is a research agent. Aquarium, a set of enterprise tools, was announced on October 23, 2026.
Sakana itself means “fish” in Japanese.
Japan’s sovereign AI ambitions
Sakana’s announcement lands inside a larger national story. Japan has been pushing for self-reliant AI development, often described as sovereign AI.
On October 23, 2026, the company launched its Recursive Self-Improvement Lab, known as the RSI Lab. The lab is focused on research into AI systems that can improve themselves over repeated cycles. Sakana has framed that work as aligned with Japan’s national strategy for sovereign AI.
The company has also built strategic partnerships with major corporations and participated in government-backed initiatives.
Disclosure: This article was edited by Diego Almada Lopez. For more information on how we create and review content, see our Editorial Policy.