FOUNDER

Founder & Operator

About the editor who designed BOOK:// and the company that runs it — and the experience this service grew out of, stated as plain fact.

STORY

What making books with a thousand people taught us.

Most people who want to make a book are not unable to write. They simply don't know where to begin, what to choose, and how to arrange it all into a book.

BOOK:// was designed by Masami Oginuma, who founded the personal-history publishing service "Asahi Jibunshi" while at The Asahi Shimbun Company. They have been part of making personal-history books with about 1,000 people, including fully bespoke volumes costing more than ¥1,000,000 each. BOOK:// turns that editorial experience into a book-making system anyone can use, powered by AI.

In that earlier work, the books were made mainly with users whose average age was around 76 — about 1,000 lives, each turned into a book. But the production style, with an editor meeting the author again and again, could exceed ¥1,000,000 per book. It was never something everyone could casually afford. BOOK:// moves that book-making knowledge into AI and rebuilds it as a system where anyone — whatever their age or profession — can make their own book.

Across those thousand books, what the editor actually did was always the same. Listen. Gather material. Choose together which stories to keep. Set the chapters in order. And polish the writing without erasing the author's own voice. BOOK://'s AI inherits that sequence exactly. That's why you don't have to start by writing — a book can begin with talking, gathering, and choosing.

BOOK:// is not a memoir service for seniors. Whatever your age or profession, it exists to turn what you want to say, keep, sell, or show into a book.

FULL ORDER
一冊のための一冊
布張り・上製本

Fully bespoke books, made with an editor at your side —
cloth-bound, casebound, sometimes more than ¥1,000,000 a copy.

Travel
Recipes
Science
Art book
Work
Family

The same editorial sequence, moved into AI —
so anyone can make a book, on any theme.

DESIGNER

The Designer

Masami Oginuma

荻沼雅美

While at The Asahi Shimbun Company, Masami Oginuma founded "Asahi Jibunshi", a personal-history publishing service. As an editor they have been part of making books with about 1,000 people — from the first interview through structure, final prose, and bookbinding. Today they lead J-Catalyst LLC and are responsible for the design and operation of BOOK://.

  • Founded "Asahi Jibunshi" (while at The Asahi Shimbun Company)
  • Involved in personal-history book-making with about 1,000 people
  • Handled fully bespoke books costing more than ¥1,000,000 a copy
  • Redesigned that editorial process into an AI system anyone can use

See the full profile

PRINCIPLES

Design promises

The rules kept across a thousand books, carried straight into the design of BOOK://.

01

The AI adds no facts beyond your material

The AI writes only from what you said and the material you added. Where something is missing, it asks you instead of filling in the gap on its own. Errors cannot be ruled out entirely, so the final check is yours. Details in How We Use AI.

02

The rights in your book are yours

Copyright in the finished book belongs to you. Sell it, give it away — it's your decision. Details in Copyright & Image Use.

03

What we can't do, we say plainly

Publishing on Amazon happens through your own KDP account. What BOOK:// provides is publishing-ready files and a step-by-step guide. What we can and cannot do is always stated as it is.

COMPANY

Operating company

CompanyJ-Catalyst LLC (Godo Kaisha J-Catalyst, Japan)
RepresentativeMasami Oginuma
BusinessPlanning and operation of the publishing platform "BOOK://"; planning and operation of information sites and cultural projects connecting Japan and the world.
WebsiteJ-Catalyst Portal
ContactContact form
BOOK:// is planned and operated by J-Catalyst LLC. It is not a service of The Asahi Shimbun Company. "Asahi Jibunshi" is a service the designer founded while at The Asahi Shimbun Company, and it is separate from BOOK://.

Make the book you want, with AI.

You don't have to start by writing. A book can begin with talking, gathering, and choosing.

Copyright

Copyright for all text, images, illustrations, design, data and systems on this site belongs to J-Catalyst LLC or the respective rights holders. Use beyond what is permitted by copyright law requires prior permission.

For quotation, coverage, republication, collaboration, or use of our data and systems, please contact us first. We will look at what you have in mind and let you know what is possible.

Contact us

© 2026 J-Catalyst LLC All rights reserved. — 2026-08-04b