#Japan #Tokyo #Tetsuo Koyama #Trynnox #Marketing Samurai

Record-Breaking Success for Tetsuo Koyama's Latest Book

In an impressive feat for the business publishing industry, Tetsuo Koyama, known as the “Marketing Samurai,” has achieved a remarkable milestone with his latest book, “Transforming into a Profitable CEO in Just One Day: The Unconventional Marketing Complete Guide.” Released in November 2025, the book has surpassed 30,000 copies in sales within just four months, prompting the announcement of a fourth print run by its publisher, KADOKAWA.

Phenomenal Initial Response

The book generated a significant buzz immediately upon release, leading to a reprint decision just ten days after its launch. With both its electronic and physical versions combined, total sales have reached 35,000 copies, reflecting the book’s widespread popularity among entrepreneurs and business leaders.

The sales figures underscore a broader trend in the publishing world. According to the Yaesu Book Center’s Weekly Rankings as of November 29, 2025, Koyama's book held the second position in both the general and business categories, highlighting its sustained appeal in a competitive market.

Reasons Behind the Book’s Success

1. Unprecedented Speed and Achievement

The swift acceleration of sales is rare in the business book genre. Achieving its first reprint within ten days is extremely unusual, and as time goes on, the book continues to shine in bestseller lists, proving that its practical insights resonate profoundly with those in leadership roles.

2. Endorsements from Influential Figures

The endorsement of the book by various prominent figures adds to its credibility. Influential personalities in investment, financial sectors, and social media have spoken highly of the book’s practicality.

• - Takashi Yamaguchi (Investment expert) emphasizes its fundamental principles of business.
• - Yuichi Sugawara (Former tax advisor) calls it a must-read for business leaders on his YouTube channel.
• - Sho Ichinosawa (CEO) recommends it for sustainable marketing strategies on social media platforms.
• - Additionally, Mitsuki Kanda utilizes Instagram to present the book as a vital resource for women entrepreneurs.

These endorsements drastically enhance the book's visibility and market reach, prompting many in the industry to explore its insights.

3. Practical Techniques for Immediate Implementation

The author’s focus on converting “intuition” into a systematic approach is perfectly timed, meeting the needs of readers looking for reliable outcomes amid economic uncertainty. Especially noteworthy are the 28 actionable methods mentioned in the book, such as specific examples of copywriting and strategies for utilizing YouTube effectively. These practical guidelines have led to organic word-of-mouth amplification across social media platforms.

Author's Perspective

In a heartfelt statement, Koyama expressed his gratitude for the book's widespread reception: “I’m sincerely thrilled that so many people are engaging with this book. In today’s world, marketing isn’t just for specialists; it’s a ‘survival strategy’ essential for all entrepreneurs and individuals. The sale of 30,000 copies reflects the immense demand for ‘fundamental earning power.’ I hope this one book serves as a weapon for challengers across Japan.”

About the Book

• - Title: Transforming into a Profitable CEO in Just One Day: The Unconventional Marketing Complete Guide
• - Author: Tetsuo Koyama
• - Release Date: November 12, 2025
• - Publisher: KADOKAWA
• - Price: ¥2,420 (tax included)
• - ISBN: 9784046075840
• - Availability: Nationwide bookstores and Amazon
• - Format: A5, 320 pages
• - Link to Amazon Product Page

About the Author

Tetsuo Koyama, born in 1982, is a successful entrepreneur and marketing consultant. He operates the YouTube channel “Unconventional Business Learning with the Marketing Samurai” and has trained over 400,000 people in various marketing principles. The YouTube channels he produces attract approximately 96 million subscribers, generating over ¥20 billion in annual revenue.

Company Overview

Founded in 2022, Trynnox is a company that embodies the philosophy of ‘No Innovation Without Challenge.’ They offer business consulting and support to enhance company growth and brand recognition. With a commitment to sustainable development, Trynnox stands as a partner for businesses looking to thrive in today’s challenging market landscape.

For more information about Trynnox:

• - Company Name: Trynnox, Inc.
• - Location: 6F, Nishishinjuku Mizuma Building, 3-3-13 Nishishinjuku, Shinjuku, Tokyo
• - CEO: Keisuke Fujimura
• - Established: August 2022
• - Business Areas: Franchise business, business consulting, business outsourcing
• - Official Website: Trynnox Official Site