Japan's Easiest-to-Understand "Digital Estate Planning & Finding Lost Digital Possessions" Practical Guide Released on April 28th
East Press Co., Ltd. released "Japan's Easiest-to-Understand Digital Estate Planning & Finding Lost Digital Possessions Practical Guide" on April 28, 2026. Authored by digital estate planning experts Kensuke Sueyoshi and Motonari Kimura, the book addresses challenges in digital estate organization, offering clear explanations with manga and illustrations on topics from password management to SNS organization and asset transfer.
📋 Article Processing Timeline
- 📰 Published: April 28, 2026 at 17:20
- 🔍 Collected: April 28, 2026 at 08:31
- 🤖 AI Analyzed: April 28, 2026 at 16:38 (8h 6m after Collected)
■ A Book Born from the Front Lines of Digital Estate Issues
"I couldn't unlock my father's smartphone..."
"When I tried to cancel, there were over 10 services I couldn't log into..."
"The deceased's SNS account was hijacked, leading to impersonation damage."
Such voices are constant on the front lines of digital estate organization.
(From a manga included in this book)
With smartphone household penetration exceeding 90%, an enormous amount of life logs are accumulated in the devices, SNS, and subscriptions we use daily. For the bereaved families, this can either be left unnoticed or unexpectedly come to light—both are problematic realities occurring in the context of inheritance.
A survey conducted by GOODREI among 323 men and women aged 40-60 revealed that 64.7% of respondents had data they "don't want to be seen" or "want deleted" in the event of their death. On the other hand, 63.5% had "not taken any specific measures"—highlighting a reality where people feel the necessity but are unable to act.
This book was written to bridge that gap.
■ For those who find it "difficult," we especially want you to pick it up
Authors Sueyoshi and Kimura, as digital forensics (electronic investigation) experts, have been involved in numerous estate organization and asset recovery cases. In recent years, with the advancement of device security, cases where unlocking and data recovery after death are physically difficult have rapidly increased.
There are limits to "fixing things after the fact."
That's why this book focuses on "what you can do starting today." It avoids difficult technical terms. With manga and illustrations, it provides practical explanations on everything from password management to SNS organization, inventorying subscriptions, and how to transfer asset information.
Just filling out one checklist can significantly reduce the burden on your family. We aimed for this book to be an opportunity to "start by talking with your loved ones."
■ Main Contents of This Book
・How to organize "invisible assets" such as accounts, passwords, and subscriptions
・How to find and leave digital possessions (practical explanation)
・Proposals for managing both paper and digital assets
・Structure that allows intuitive understanding with manga and illustrations
・Includes a checklist that anyone can start immediately
■ Table of Contents
Chapter 1: The Full Scope of Digital Assets Without Physical Form
Chapter 2: Can't Open My Smartphone—The "Biggest Hurdle" Where Everything Stops
Chapter 3: Investigation and Inheritance Procedures for Intangible Financial Assets
Chapter 4: Billing Doesn't Stop After Death—Practicalities of Canceling Subscriptions
Chapter 5: Extremely Difficult-to-Find Assets—Special Circumstances of Cryptocurrencies and Overseas Assets
Chapter 6: The Complete Guide to Creating a "Digital Asset Notebook" to Protect Your Family
Chapter 7: Securely Hiding What You Don't Want Seen—Four Methods for Privacy Protection
■ Book Overview
Title
Japan's Easiest-to-Understand "Digital Estate Planning & Finding Lost Digital Possessions" Practical Guide
Authors
Kensuke Sueyoshi, Motonari Kimura
Release Date
April 28, 2026
Price
1,650 yen (1,500 yen + 10% tax)
Format/Pages
A5 size・232 pages
Publisher
East Press Co., Ltd.
ISBN
978-4-7816-2534-8
Book Details/Purchase
https://www.eastpress.co.jp/goods/detail/9784781625348
■ Publisher Information
Company Name
East Press Co., Ltd.
Location
Hirose Building 7F, 3-17 Kanda Nishikicho, Chiyoda-ku, Tokyo 101-0054
TEL / FAX
TEL 03-5213-4700 / FAX 03-5213-4701
URL
https://www.eastpress.co.jp
■ Adopted by Library Distribution Center's "New Book Express Bell"
This book has been selected as an adopted title for the "New Book Express Bell" by the Library Distribution Center (TRC). It is expected to be acquired by public libraries nationwide.
Among over 70,000 new books published annually, Bell adoption is a very narrow gate, signifying recognition as an "important book that should be held in libraries."
■ Author Profiles
Kensuke Sueyoshi
Born in 1986, from Chiba Prefecture. After graduating from Toyo University's Faculty of Law, he worked as a trader at a securities company before starting his own business. In 2022, he transitioned to data recovery and cybersecurity, launching a digital estate organization business applying forensic technology. Representative of GOODREI Co., Ltd.
Motonari Kimura
Born in 1989. After research and development at a major manufacturer, he transitioned to a security engineer. He has been involved in strengthening organizational security systems, including digital forensic investigations and leading ISMS certification projects. He addresses digital estate issues by combining his knowledge as an inheritance diagnostician and IT technology. Affiliated with GOODREI Co., Ltd.
"I couldn't unlock my father's smartphone..."
"When I tried to cancel, there were over 10 services I couldn't log into..."
"The deceased's SNS account was hijacked, leading to impersonation damage."
Such voices are constant on the front lines of digital estate organization.
(From a manga included in this book)
With smartphone household penetration exceeding 90%, an enormous amount of life logs are accumulated in the devices, SNS, and subscriptions we use daily. For the bereaved families, this can either be left unnoticed or unexpectedly come to light—both are problematic realities occurring in the context of inheritance.
A survey conducted by GOODREI among 323 men and women aged 40-60 revealed that 64.7% of respondents had data they "don't want to be seen" or "want deleted" in the event of their death. On the other hand, 63.5% had "not taken any specific measures"—highlighting a reality where people feel the necessity but are unable to act.
This book was written to bridge that gap.
■ For those who find it "difficult," we especially want you to pick it up
Authors Sueyoshi and Kimura, as digital forensics (electronic investigation) experts, have been involved in numerous estate organization and asset recovery cases. In recent years, with the advancement of device security, cases where unlocking and data recovery after death are physically difficult have rapidly increased.
There are limits to "fixing things after the fact."
That's why this book focuses on "what you can do starting today." It avoids difficult technical terms. With manga and illustrations, it provides practical explanations on everything from password management to SNS organization, inventorying subscriptions, and how to transfer asset information.
Just filling out one checklist can significantly reduce the burden on your family. We aimed for this book to be an opportunity to "start by talking with your loved ones."
■ Main Contents of This Book
・How to organize "invisible assets" such as accounts, passwords, and subscriptions
・How to find and leave digital possessions (practical explanation)
・Proposals for managing both paper and digital assets
・Structure that allows intuitive understanding with manga and illustrations
・Includes a checklist that anyone can start immediately
■ Table of Contents
Chapter 1: The Full Scope of Digital Assets Without Physical Form
Chapter 2: Can't Open My Smartphone—The "Biggest Hurdle" Where Everything Stops
Chapter 3: Investigation and Inheritance Procedures for Intangible Financial Assets
Chapter 4: Billing Doesn't Stop After Death—Practicalities of Canceling Subscriptions
Chapter 5: Extremely Difficult-to-Find Assets—Special Circumstances of Cryptocurrencies and Overseas Assets
Chapter 6: The Complete Guide to Creating a "Digital Asset Notebook" to Protect Your Family
Chapter 7: Securely Hiding What You Don't Want Seen—Four Methods for Privacy Protection
■ Book Overview
Title
Japan's Easiest-to-Understand "Digital Estate Planning & Finding Lost Digital Possessions" Practical Guide
Authors
Kensuke Sueyoshi, Motonari Kimura
Release Date
April 28, 2026
Price
1,650 yen (1,500 yen + 10% tax)
Format/Pages
A5 size・232 pages
Publisher
East Press Co., Ltd.
ISBN
978-4-7816-2534-8
Book Details/Purchase
https://www.eastpress.co.jp/goods/detail/9784781625348
■ Publisher Information
Company Name
East Press Co., Ltd.
Location
Hirose Building 7F, 3-17 Kanda Nishikicho, Chiyoda-ku, Tokyo 101-0054
TEL / FAX
TEL 03-5213-4700 / FAX 03-5213-4701
URL
https://www.eastpress.co.jp
■ Adopted by Library Distribution Center's "New Book Express Bell"
This book has been selected as an adopted title for the "New Book Express Bell" by the Library Distribution Center (TRC). It is expected to be acquired by public libraries nationwide.
Among over 70,000 new books published annually, Bell adoption is a very narrow gate, signifying recognition as an "important book that should be held in libraries."
■ Author Profiles
Kensuke Sueyoshi
Born in 1986, from Chiba Prefecture. After graduating from Toyo University's Faculty of Law, he worked as a trader at a securities company before starting his own business. In 2022, he transitioned to data recovery and cybersecurity, launching a digital estate organization business applying forensic technology. Representative of GOODREI Co., Ltd.
Motonari Kimura
Born in 1989. After research and development at a major manufacturer, he transitioned to a security engineer. He has been involved in strengthening organizational security systems, including digital forensic investigations and leading ISMS certification projects. He addresses digital estate issues by combining his knowledge as an inheritance diagnostician and IT technology. Affiliated with GOODREI Co., Ltd.