The First Year of a Society with a Declining Population--Companies that Survive Win through Diversification The "Hongo no Keiei Notebook 2026" (Management Notebook 2026) March 18 (Wednesday), 2012 - 16th in the series

Toho Shobo Co. (Head office: Shinjuku-ku, Tokyo; Representative Director: Kei Kagamibuchi) will release on March 18, 2026 (Wednesday), a management book "Hongo's Management Notebook 2026" proposed by the author, a "management professional" who is the creator of the largest tax accounting firm in Japan and has both an accounting and tax perspective and a corporate management perspective. A Small Proposal for Diversification and Survival in a Society with a Declining Population" by Kohiro Hongo (price: 1,760 yen including tax) will be released.

Book Shadow

Book introduction site

https://tohoshobo.info/?p=2275

The population of Shimane Prefecture will decrease by approximately 620,000 people, or roughly the population of one prefecture, in one year from 2024 to 2025 (Shimane Prefecture has a population of approximately 640,000, see Statistics Bureau, Ministry of Internal Affairs and Communications). This book, the 16th in the series, discusses how companies can survive and grow in a shrinking market under the theme of "the first year of a society with a declining population.

In Chapter 1, we find business models in the era of declining population in diversification strategies. Chapter 2, learning from history such as the Edo period and Western Europe after the Black Death, shows that structural reform from "quantity" to "quality" is essential. Chapter 3, while analyzing the impact of population decline on sales, human resources, and infrastructure, explains the importance of financial strategies to obtain "residual profit"; Chapter 4, describes how to utilize and face AI, which is important in the era of population decline; and Chapter 5, examines specific measures for diversification strategies based on corporate research.

The "Management Notebook" has been written concurrently with the practice of running an accounting firm. This management book is full of hints for managers to think and practice by themselves.

Outline of "Hongo's Management Notebook 2026

Subtitle: Business Models in a Declining Population Society are Diversified, A Small Proposal for Survival

Publication Date ：March 18, 2026 (Wednesday)

Format : 46x4

Number of pages: 131

Price: 1,760 yen (including tax), 1,600 yen + tax

Author ：Kohiro Hongo

Illustration : Tomomi Michibata

Table of Contents

Introduction

Chapter 1: Business Models and Growth Strategies in an Era of Declining Population

　1 A Society with a Declining Population is a Regionalized Nation

　2 Conglomerate Premium!

　3 GAFAM's Speed Diversification

　4 Learn from regional allies (zaibatsu)

　5 Formation of zaibatsu in Meiji era was a model → Japan was a pioneer in everything

　6 Digitalization makes it easy to expand into other industries (diversification)

　7 Compatibility of Holdings (Holding Company) and Conglomerates

　8 Diversification marketing is SNS (aerial warfare) x ground warfare

Chapter 2: Historical Perspectives on the Era of Declining Population

　1 Learning from the Edo Period

　2 Major historical examples of how population decline could be prolonged through qualitative transformation

　3 Life-extending measures are qualitative transformation and structural reform

　4 Winning in cities!

　5 Making History Work for Business

Chapter 3: Impact of Population Decline on Business

　1 Shrinking domestic market and decreasing demand

　2 Worsening labor shortage

　3 Change in customers → Aging population and solo society

　4 Lack of infrastructure and weak supply chain

　5 Political stability

　6 Declining population < decrease in business establishments

Chapter 4: AI becoming a smartphone

　1 AI is a strategic weapon in an era of declining population

　2 Unknowing is Top → AI is Top Matter

　3 Aim!　AI that even monkeys can do

　4 AI is the Age of Useware

　5 AI is the ultimate weapon for SMEs

Chapter 5: Diversified Models

　1 Furukawa Model

　2 Mitsubishi Estate and Mitsui Fudosan

　3 Sekisui House and Daiwa House Industry (Daiwa House)

　4 ORIX's Diversification Strategy

　5 Diversification by leveraging existing customer base

Our Group's initiatives in the shy (in lieu of a conclusion)

■Author Profile

Author：Yoshihiro Hongo

Certified public accountant and tax accountant. Chairman of the Tsuji/Hongo Group.

Graduated from Waseda University, Faculty of Political Science and Economics I, and completed the master's course at the Graduate School of Commerce, Waseda University.

He joined Showa Audit Corporation (currently Ernst & Young ShinNihon LLC) in 1972, registered as a certified public accountant in 1975, and established Hongo Certified Public Accountant Office in 1977. With the establishment of the Certified Public Tax Accountant system, he founded Tsuji & Hongo Tax Corporation in April 2002 and, as Chairman, has developed it into one of the largest tax accounting firms in Japan. As an accounting specialist, he has been involved in accounting taxation for half a century and has interacted with executives, entrepreneurs, and celebrities from various fields He has been in his current position since 2016.

He has been a lecturer at the University of Tokyo, a lecturer at Tokyo University of Science, and a visiting professor at Kanagawa University's Institute of Small Business Management and Accounting. With the motto "Don't leave taxation, don't stick to taxation," he is an energetic writer in the fields of taxation and management strategy, utilizing his strengths in expertise, writing, and speaking skills.

His recent publications include "Hongo no Keiei Note 2025" and "80-sai kara no Kuzoku to Maze (80-sai Kara no Kuzoku to Maze)" (Toho Shobo), as well as many other books.

Outline of the Tsuji/Hongo Group

With Tsuji & Hongo Tax Corporation, one of the largest tax firms in Japan, at its core, the Tsuji & Hongo Group is a professional group that provides one-stop solutions to corporate management issues, including consulting, IT, M&A, and asset management. With more than 85 offices nationwide, a staff of over 2,200, and an extensive track record of supporting more than 20,000 corporate clients, the group supports the sustainable growth of companies with multifaceted solutions that anticipate the changing times.

Major Constituent Corporations

Tsuji Hongo Tax Corporation

Tsuji-Hongo Business Consulting Co.

SBI Tsuji-Hongo M&A Corporation

CS Accounting Co.

Tsuji-Hongo Insurance Co.

Tsuji-Hongo IT Consulting Co.

Hongo Medical Solutions Co.

Tsuji Hongo Audit Corporation

Tsuji Hongo FAS Co.

Tsuji Hongo Family Office Co.

Tsuji Hongo CFO Co.

https://www.ht-tax.or.jp/

Company Profile: Toho Shobo Co.

(1) Company name: TOHOSHOBO Corporation (https://tohoshobo.info/)

　 English name: TOHOSHOBO INC.

(2) Representative: Takashi Kagamibuchi, Representative Director

(3) Head office: 4-2-20 Shinjuku, Shinjuku-ku, Tokyo

(4)Main business: Publishing of business books

(5)Capital ：35 million yen