Seed Round Investment in Fusion Energy startup MiRESSO


Genesia Ventures has announced its investment in MiRESSO, a company that aims to contribute to the implementation of fusion power generation by ensuring a stable supply of necessary mineral resources like beryllium. The investment was made in MiRESSO’s seed funding round.


MiRESSO, a fusion energy startup certified by the National Institute of Quantum Science and Technology (QST), has made significant strides in reducing the cost of beryllium refining. Led by CEO Masaru Nakamichi, the team has developed a low-temperature refining technology (patent pending) that combines chemical processing with microwave heating. Unlike traditional methods, which require temperatures over 2000°C, this new technology enables easy dissolution of beryllium ore at a much lower temperature of 300°C and atmospheric pressure. This innovative approach not only revolutionizes beryllium refining by making it more cost-effective and energy-efficient, but also addresses procurement challenges related to beryllium in fusion power generation. Consequently, it opens up possibilities for the wider adoption of fusion power by ensuring a stable supply of mineral resources.

Business Background

Fusion reactors are power generation systems that harness electricity from fusion energy, which uses deuterium and tritium in a plasma state as fuel. However, since tritium is rarely found in nature, it must be produced within a device surrounding the plasma, known as the blanket. This production process requires a substantial amount of beryllium (Be), a neutron multiplier that doubles the number of neutrons from one to two.


However, procuring beryllium presents several significant challenges. The current price of beryllium is very high, and the global production is markedly inadequate to meet the demand for even one fusion prototype reactor, which requires more beryllium than the current total world production. Therefore, securing beryllium consistently and at a low cost is considered a critical issue for the realization of fusion prototype reactors, which are currently under design consideration.

Purpose of Fundraising

  1. Accelerating the Pilot Demonstration of Beryllium Refining In October 2023, MiRESSO was selected for a SBIR Phase 3 by the Ministry of Education, Culture, Sports, Science and Technology ( for the scale-up demonstration of low-temperature refining technology. The aim is to construct and demonstrate a pilot plant with a production capacity of 1 ton of beryllium per year by 2027. This fundraising will accelerate the demonstration of this pilot plant.
  2. Strengthening the Team In anticipation of future business expansion, the company plan to recruit talent for various roles. These include CXO positions, business development, plant engineering, research, and technology development, and this effort aims to strengthen its team structure.
  3. Launching the Technology Platform Business MiRESSO’s low-temperature refining technology can be applied to the refining and recycling processes of other resources and materials, such as rare metals and rare earths, which typically require high-temperature processing. Therefore, using MiRESSO’s low-temperature refining technology as a platform, the company will conduct research and development tailored to the materials and challenges its clients face. Additionally, it will propose process improvements, equipment introductions, and technical licensing to implement these solutions, marking the official launch the technology platform business.

About the Investment

Masafumi Kawai, Partner at Genesia Ventures

While there is growing anticipation for fusion as a technology that can fundamentally solve energy and environmental issues, one of the concerns is the supply constraint of beryllium, necessary for tritium production. MiRESSO’s low-temperature refining technology addresses this challenge and accelerates the implementation of fusion. Although commercialization of fusion power generation may still take some time, we see several appealing aspects in MiRESSO. One is its unique position in supplying materials for fusion reactors, aimed at the construction of prototype reactors in the upcoming demonstration phase. Another is the application of its refining technology to minerals other than beryllium, paving the way for relatively early commercialization. Through MiRESSO, we aspire for Japan to lead the global market in fusion energy, anticipated to be a future mega-industry, and contribute to energy security and a stable supply of strategic materials.

Company Profile

Company Name : MiRESSO
Establishment : March 2023
Location : Azasimokubo59-383 , Misawa, Misawa Shi, Aomori