The Essence of Japanese
Fermentation,
to the World.
Koso-buro: A Japanese Wellness Experience
Powered by Natural Fermentation.
What Is Koso-buro?
An Authentic Japanese Fermentation-Based Wellness Experience.
Koso-buro, also known as a Japanese Enzyme Bath, is a traditional Japanese dry bathing experience powered by natural microbial fermentation.
Organic materials such as rice bran and sawdust naturally generate heat through fermentation. Guests are gently covered in the warm material, experiencing a distinctive form of Japanese wellness unlike conventional baths or saunas.
The fermentation material can reach approximately 60–70°C (140–158°F) through natural biological activity, without relying on external heating to generate the bath’s heat.
A Japanese Tradition.
A New Opportunity for Your Market.
Koso-buro offers wellness entrepreneurs an opportunity to introduce a distinctive Japanese concept that is still largely unknown in many international markets.
Rooted in Japan’s fermentation culture, Koso-buro combines tradition, natural processes, and a unique wellness experience in a way that sets it apart from conventional spas and saunas.
For entrepreneurs looking to bring something new to their local wellness market, Koso-buro offers the potential to create a distinctive business built around an authentic Japanese concept.
Bring the culture of Japanese fermentation to your market — and create a wellness experience your customers have never encountered before.
Strategic Advantages
Five Reasons to Bring Koso-buro to Your Market.
01
A Distinctive Wellness Concept
Stand apart from conventional spas and saunas with an authentic Japanese wellness experience powered by natural fermentation.
02
Powered by Natural Fermentation
The bath is naturally heated through microbial fermentation, without relying on an external heat source.
03
Circular Use of Local Resources
Explore the potential to use locally available organic materials such as rice bran and sawdust, with spent materials suitable for reuse in applications such as composting.
04
Flexible Facility Design
Adapt the Koso-buro concept to a variety of spaces, from dedicated wellness facilities to spas and other hospitality environments.
05
A Repeatable Wellness Experience
Create a distinctive wellness experience that can become part of your customers’ regular self-care routines.
Our Support System
More Than Materials. We Build With You.
From feasibility assessment to launch and ongoing operation, we provide hands-on support to help you establish Koso-buro in your market.
01 ASSESS
Local Feasibility Assessment
We assess locally available materials, climate conditions, and the proposed facility environment to determine the feasibility of establishing Koso-buro in your location.02 SET UP
Starter Culture & Fermentation Setup
We provide our proprietary fermentation starter and guide the preparation and activation of the Koso-buro fermentation environment using suitable materials available in your region.03 LAUNCH
On-Site Launch & Staff Training
Our team provides on-site support during the launch period, helping set up the fermentation process and training your staff in daily operation, maintenance, and customer service.04 SUPPORT
Ongoing Remote Support
After opening, we continue to support your operation remotely, helping you monitor fermentation conditions, review photos, videos, and temperature records, and troubleshoot issues as they arise.From First Consultation to Launch — and Beyond.
A clear, step-by-step process designed to guide you from your first consultation through the launch of your Koso-buro business and beyond.
PHASE 01
DISCOVER
01 Inquiry
Contact us and tell us about your interest in bringing Koso-buro to your market.
02 Online Consultation
We discuss your vision, target market, location, business concept, and initial requirements.
PHASE 02
ASSESS
03 Local Material Research
We explore the availability of suitable local materials such as rice bran and sawdust.
04 Feasibility Assessment
We assess local conditions, available materials, and the proposed facility environment to determine the feasibility of establishing Koso-buro in your location.
PHASE 03
PLAN
05 Project Proposal
Based on our assessment, we develop a launch plan tailored to your location and business concept.
06 Agreement
Once the project scope, responsibilities, schedule, and costs are confirmed, we proceed with the agreement.
07 Facility Preparation
You prepare the facility and necessary equipment according to the agreed specifications and our guidance.
PHASE 04
LAUNCH
08 Starter Culture Preparation & Shipping
We prepare and arrange the fermentation starter required to establish your Koso-buro.
09 On-Site Fermentation Setup
Our team provides on-site support for the initial setup and activation of the fermentation environment at your location.
10 Staff Training
Your team receives practical training in daily fermentation management, operation, maintenance, and customer service.
11 Pre-Opening Preparation
Before opening, we check the fermentation conditions and operational setup together to ensure your team is ready for launch.
PHASE 05
SUPPORT
12 Ongoing Remote Support After opening, we continue to support your operation remotely, helping you monitor fermentation conditions, review operational data, and troubleshoot issues as they arise.
Investment & Costs
Transparent. Practical. Built for Long-Term Operation.
Every Koso-buro project is tailored to the local environment, available materials, facility conditions, and business requirements. Final costs are determined after the initial consultation and feasibility assessment.
INITIAL PROJECT FEE
From
€50,000
US$50,000
per location
Complete support from planning through launch.
MONTHLY SUPPORT
From
€500
US$500
/ month
Ongoing fermentation management and remote support.
WHAT’S INCLUDED
Online pre-project consultation
Initial assessment of locally available materials
Technical guidance for facility planning
Fermentation starter for the initial launch
Fermentation techniques & management know-how
Approximately one month of on-site technical support
Hands-on staff training
Pre-opening fermentation management support
Fermentation management manual
Remote support for the agreed period
WHAT’S NOT INCLUDED
Additional costs may apply depending on local materials, climate conditions, regulatory requirements, and project scope. Unless otherwise agreed, expenses not included in the basic project fee are the responsibility of the local operator.
Monthly Support
Ongoing Expertise for Stable Fermentation Management.
After the on-site launch support is completed, we continue to assist your team remotely by reviewing photos, videos, temperature records, and other available information.
REMOTE FERMENTATION SUPPORT
Our remote support helps your team maintain and adjust the fermentation environment as local conditions change throughout the year.
Because some fermentation issues cannot be fully assessed online, additional on-site support may occasionally be required.
International shipping, customs duties, import taxes, and local delivery costs are not included. Import requirements, storage, and use of the fermentation liquid must be confirmed by the local operator in accordance with applicable local laws and regulations. The frequency, method, availability, and contract period of remote support are defined in each individual agreement. Additional on-site visits, training, or setup of new fermentation baths will be quoted separately.
Partnership & Terms
Built on Clear Roles and Shared Responsibility.
Establishing Koso-buro in a new market requires close collaboration. We provide the fermentation expertise and launch support, while our local partners manage the facility, regulatory requirements, and day-to-day business operations.
WE PROVIDE
Technical Expertise
Fermentation knowledge, launch support, on-site guidance, and staff training.
YOU OPERATE
Local Management
Your team manages the facility, local materials, staff, permits, and day-to-day business operations.
WE CONTINUE
Ongoing Partnership
After launch, we continue to support your team remotely with fermentation management and operational guidance.
ABOUT US & VISION
Bringing Japanese Fermentation Culture to the World.
At FREELY, we believe that Japan’s fermentation culture has the potential to inspire a new approach to wellness around the world.
Through Koso-buro, we aim to share not only a unique wellness experience, but also the knowledge, craftsmanship, and culture of fermentation that have been cultivated in Japan.
Our vision is to work with local partners to bring Koso-buro to new communities while respecting local environments, materials, and cultures.
OUR FOUNDER
The Vision Behind Koso-buro’s Global Expansion.
Founder & President, WORLD ENZYME BATH FEDERATION
Kyoko Oshita is a Japanese fermentation bath producer dedicated to bringing the culture and practice of Koso-buro to new markets around the world.
Through FREELY Inc., she supports the development and launch of Koso-buro businesses, combining hands-on experience in fermentation management with practical guidance for facility setup, staff training, and ongoing operation.
Her mission is to preserve the knowledge behind Japanese fermentation bathing while adapting the concept thoughtfully to local materials, environments, and cultures.
As part of our European expansion, FREELY plans to establish a local office in Amstelveen, the Netherlands, in 2027.
