InnerSource Gathering Tokyo 2025 Event Report
The InnerSource Gathering Tokyo 2025 concluded successfully on September 12, 2025. The event brought together professionals and enthusiasts to explore the secrets of cross-organizational collaboration in software development. It was a wonderful showcase of the continued growth and enthusiasm of the InnerSource community in Japan.
Acknowledgements
This event’s success would not have been possible without the support of many people:
- All participants who joined us
- Speakers who shared their excellent insights and experiences
- Sponsors who provided venue and support:
- Venue Sponsor: NTT DOCOMO, Inc. (docomo R&D OPEN LAB ODAIBA)
- Gold Sponsor: Mitsubishi Electric Corporation
- Silver Sponsor: KDDI Agile Development Center Corporation
- Everyone involved in the InnerSource community on a regular basis
When we first launched this community, the term “InnerSource” was hardly known in Japan. Now, many people are interested in this concept and have begun implementing it. Thanks to all of you, we continue to spread the concept and practice of InnerSource in Japan. We sincerely thank you.
If you’re interested in the InnerSource community, please join us through the link below. We share the latest information on InnerSource and exchange information about community activities.
👉 Link to InnerSource Commons Slack (You can converse in Japanese in the #japan channel)
We look forward to continuing to walk together towards the development of the InnerSource community. Let’s meet again at the next event!
InnerSource Gathering Tokyo 2025 Executive Committee
Sessions
The event featured many excellent sessions from practitioners across Japan. Below is a list of the sessions with links to videos and resources.
| Session | Speaker | Video | Resources |
|---|---|---|---|
| Welcome to InnerSource Gathering Tokyo 2025 | Shoma Kubo | Video | |
| Venue Introduction | NTT DOCOMO, Inc. | Video | |
| Keynote: Building the Future with InnerSource | Masanori Kado | Video | Slides |
| InnerSource Activity ‘xPalette’ Unleashing Engineers’ Creativity and Initiative | Takahiro HIRUMA | Video | |
| Mitsubishi Electric’s InnerSource Future - Invitation to InnerSource Summit 2025 | Shingo Oidate | Video | |
| InnerSource Dialogue | Ippei Kumagawa, Yoshitake Kobayashi | Video | |
| Message from InnerSource Hero | Tomohiro Nakajima | Video | |
| Why Are We Here - The Expression and Process in the Era of Individual Choice | Yuki Izumoto | Video | Slides |
| Nurturing InnerSource for Scaling Organizations | Leona Matsumoto | Video | Slides |
| InnerSource OST (Open Space Technology) | All Participants |
Welcome to InnerSource Gathering Tokyo 2025
Shoma Kubo (AEON Smart Technology Co., Ltd. / InnerSource Commons Foundation)
Opening remarks welcoming everyone to InnerSource Gathering Tokyo 2025.
Venue Introduction
NTT DOCOMO, Inc. (Venue Sponsor)
Introduction to the venue at docomo R&D OPEN LAB ODAIBA.
Keynote: Building the Future with InnerSource
Masanori Kado (Representative Director, Wycle Inc.)
The keynote focuses on the culture and customs valued in the FOSS world, and the people involved. It explains open cooperation and learning from each other. Introducing the translated book “Forge Your Future with Open Source,” it provides hints for those who want to incorporate FOSS practices into their learning and work. Finally, it connects these concepts to InnerSource initiatives within organizations and introduces methods to update organizational culture and ways of working.
InnerSource Activity ‘xPalette’ Unleashing Engineers’ Creativity and Initiative
Takahiro HIRUMA (Nomura Research Institute, Production Innovation Center, Platform Service Development Department 2)
In an organization centered on software provision and maintenance services, drawing out engineers’ creativity and initiative is essential for growth. This requires not just top-down promotion, but flat and open spaces where engineers want to participate. The InnerSource community ‘xPalette’, launched as such a space, is now in its fourth year. Through ‘xPalette’, the organization’s capabilities (technical skills) have expanded, and member participation in projects utilizing these capabilities has increased. Furthermore, the creation of new businesses combining multiple capabilities is specifically progressing. This session looks back on ‘xPalette’s journey and introduces tips and practical examples useful for operating InnerSource communities.
Mitsubishi Electric’s InnerSource Future - Invitation to InnerSource Summit 2025
Shingo Oidate (General Manager, Open Source Co-Creation Promotion Department, Design Technology Development Center, Mitsubishi Electric Corporation)
Mitsubishi Electric’s OSPO (Open Source Program Office), the Open Source Co-Creation Promotion Department established in April 2025, is accelerating internal and external co-creation through both open source and InnerSource. As a result, the internal InnerSource community has achieved rapid growth. This session shares behind-the-scenes stories of the organization’s establishment and practical examples of community expansion, while introducing the “InnerSource Summit 2025” hosted by Mitsubishi Electric on November 13, 2025.
InnerSource Dialogue
Ippei Kumagawa (Representative of ican.lab, Quality Management Expert)
Yoshitake Kobayashi (Toshiba Corporation, Digital Innovation Technology Center)
A dialogue session with Ippei Kumagawa, who practiced InnerSource in large enterprises and continues to work at the forefront of organizational culture transformation and engineer development even after becoming independent. This session explores the “real co-creation” that transcends organizational and individual boundaries. From success stories and culture transformation processes, it explores the true value of InnerSource that goes beyond simply “building together.” It shares hints for involving people and improving quality directly connected to user experience and deliverable value. This is a session where you can experience the possibilities of organizational transformation and value creation born from co-creation.
Message from InnerSource Hero
InnerSource Hero / Tomohiro Nakajima (KDDI Agile Development Center)
A message from InnerSource Hero, who stood up last year to break down organizational silos.
Why Are We Here - The Expression and Process in the Era of Individual Choice
Yuki Izumoto (Scrum Master, KDDI Agile Development Center Corporation)
In an era where each person chooses their organization - or about the commitment to expression and process for “why are we here” - or about KAGreement challenging culture formation through open communication and open collaboration.
Among countless companies in the world, why do we continue to work here? It’s probably because there is compatibility and conviction between the organization and the individual. In other words, once that compatibility breaks down, we may feel anxiety or dissatisfaction with our sense of existence and identity within the organization. In response to such questions, let me talk about KAGreement, which is challenging culture formation with thinking very similar to InnerSource, incorporating my experiences and feelings.
Nurturing InnerSource for Scaling Organizations
Leona Matsumoto (Package Team Engineer, teamLab Inc.)
Nurturing a culture where InnerSource is created is very important. However, InnerSource truly demonstrates its effect when it is actually used, receives feedback, and is improved. This session introduces know-how for nurturing InnerSource and scaling organizations.
InnerSource OST
Open Space Technology (OST) is a discussion format session to gain deep insights on topics important to participants.
All participants engaged in meaningful discussions about InnerSource topics that matter to them.
Organizers Wanted!
This event is organized by a volunteer group of organizers.
We are recruiting organizers for the next event. If you are interested, please feel free to reach out!
Let’s liven up the community together!
We are waiting for you in the #japan channel on InnerSource Commons Slack.