<h3>He started with 500,000 yen at age 20 while still in college and became an “Okuribito” (a person who has earned over 100 million yen through investing) at 29.</h3>
<p>The term “Okuribito” refers to investors who have built up assets worth hundreds of millions of yen. This time, we feature Tāchan, who began developing his own value stock investing strategy as a university student and has since amassed more than 5 billion yen in stock assets. By systematizing and refining his practical approach to value investing, Tāchan reminds us that stock investing can yield profits if you take the time to carefully select your stocks.</p>
<figure id="attachment_439916" class="wp-caption alignnone" style="width: 640px;" aria-describedby="caption-attachment-439916"><a href="#" data-ident_hash="b7e3244f"><img src="https://res.cloudinary.com/fridaydigital/image/private/t_article_image/wpmedia/2025/09/d1e78427e9569b9e7ddc5e1fbc0df94e.jpg" alt=""></a><figcaption id="caption-attachment-439916" class="wp-caption-text">What is the value stock investing method — independently developed during his college years — that enabled this Okuribito (investor with over 5 billion yen in stock assets) to build a fortune exceeding 5 billion yen?</figcaption></figure>
<p>[Profile: Tāchan]</p>
<p data-start="25" data-end="131">Born in Hyōgo Prefecture in 1975. A physician who graduated from a national university’s medical school. At age 20, while still in university, he read Robert Kiyosaki’s Rich Dad Poor Dad, which sparked his interest in investing. Starting with 500,000 yen in seed money, he began investing in stocks. Through self-study, he discovered value stock investing during his student years. By focusing his own method—concentrated investments in self-selected value stocks—he became an Okuribito (an investor with over 100 million yen in assets) at age 29.</p>
<p data-start="588" data-end="805">Although his funds temporarily decreased during the 2008 Lehman Shock, he did not alter his investment style and steadily grew his assets. With the tailwind of Abenomics, his net worth reached 1 billion yen by 2013. After a period of plateau, his passion for investing was reignited when he was diagnosed with rectal cancer in 2022. Through concentrated investments in shipbuilding stocks, his assets reached 5 billion yen by 2024. After four surgeries, however, metastases to his lungs and liver were discovered in 2024 at age 49. His doctor has told him, “You may make it to 50, but 51 is uncertain.”</p>
<figure id="attachment_439917" class="wp-caption alignnone" style="width: 1121px;" aria-describedby="caption-attachment-439917"><a href="#" data-ident_hash="2855886a"><img src="https://res.cloudinary.com/fridaydigital/image/private/t_article_image/wpmedia/2025/09/d022bc7a7bbba3dffe4a7f2d273fbdf8.jpg" alt=""></a><figcaption id="caption-attachment-439917" class="wp-caption-text">While battling terminal cancer, he wrote a heartfelt message to his daughter. His book, “Lessons from a Father Who Turned 500,000 Yen into 5 Billion: A Message from an Investor Father to His Daughter” (Diamond, Inc.), has surpassed 120,000 copies sold!</figcaption></figure>
<h3>It’s something we think we know—but do we really?<br data-start="49" data-end="52">The surprisingly vague concept of <strong data-start="86" data-end="105">value stocks.</strong></h3>
<p data-start="107" data-end="195">The investor featured this time, Ta-chan, is a true master of value investing.</p>
<p data-start="197" data-end="484">A value stock is essentially a bargain stock, defined as a company whose stock price is lower than its intrinsic value as measured by investment indicators. When the market eventually recognizes the true worth of such a company, its stock price is expected to rise to a fair level.</p>
<p data-start="486" data-end="880">So how are value stocks discovered? In general, value investors rely on metrics such as PER (Price Earnings Ratio) and PBR (Price Book-value Ratio). Using a brokerage’s stock screening tools, they might set conditions like PER below 10 or PBR below 0.8 to extract undervalued stocks. From there, they narrow down candidates by evaluating business performance and financial health.</p>
<p data-start="882" data-end="1321">However, this common approach has a major flaw: it doesn’t clarify what truly makes a stock undervalued.<br data-start="988" data-end="991">While it may find stocks with lower PER or PBR compared to market averages, that’s merely a relative judgment. Changes in market conditions, exchange rates, or the economy can easily erase that sense of cheapness. In the end, it may amount to nothing more than buying a low-priced stock—without understanding its real value.</p>
<p data-start="1323" data-end="1514" data-is-last-node="" data-is-only-node="">In contrast, Ta-chan digs deeper into what specifically makes a company undervalued.<br data-start="1413" data-end="1416">His unique method sharpens the definition and practice of value investing with remarkable clarity.</p>
<h3>Investment Methods That Evolve with a Company’s True Value</h3>
<p data-start="64" data-end="265">Ta-chan defines a company’s value as <strong>“owned assets + future profits.”</strong><br data-start="137" data-end="140">Based on this, he created the following formula for stock prices:<br data-start="205" data-end="208"><strong>Stock Price = Owned Assets + Future Profits (+ Bias).</strong></p>
<p data-start="64" data-end="265">“Bias,” he explains, <strong>“refers to investors’ prejudices—like ‘this company’s stock will definitely rise’ or ‘this company has no future.’ In theory, a company’s stock price should align with its actual value, but once these biases are added in, prices can become overvalued or undervalued. </strong><strong>To succeed in value investing, it’s essential to remove such biases and focus purely on the company’s true value.”</strong> (Ta-chan)</p>
<p data-start="691" data-end="766">Ta-chan’s value investing strategy can be divided into three types:<strong> 1. Asset Value Investing – focuses on a company’s owned assets. 2. Earnings Value Investing – emphasizes future profit potential. 3. Cyclical Value Investing – targets stocks whose prices are undervalued due to biases, even when both their assets and future profits are sound.</strong></p>
<p data-start="1074" data-end="1274">By classifying investments in this way, it becomes clear what exactly is undervalued and why it’s considered undervalued—resolving the ambiguity that often clouds conventional value investing.</p>
<p data-start="1276" data-end="1389">As Ta-chan notes, the difficulty of each approach—and the potential returns—both increase in the order above.</p>
<p data-start="1391" data-end="1648" data-is-last-node="" data-is-only-node="">He refers to these as his three truly profitable investment strategies.<br data-start="1468" data-end="1471">Details on his current portfolio, his outlook on the stock market, and the stocks he’s currently watching are shared in the premium edition of <strong>FRIDAY Subscription.</strong></p>
<div data-friday-gold-link-url="https://friday.gold/article/365988" data-friday-gold-link-title="The amazing &quot;value stock investment&quot; technique that increased 500,000 yen to 5 billion yen...A book by a doctor and individual investor who was told he did not have long to live is a topic of conversation." data-friday-gold-link-excerpt="Billionaire&quot; refers to an investor who has amassed assets in the hundreds of millions of yen. The man who appears in this issue is Mr. Ta-chan, who has built up a stock portfolio of over 5 billion yen using &quot;value stock investment,&quot; which he originally established when he was a university student. Often summed up in one word" data-friday-gold-link-thumbnail-wide="https://assets.friday.gold/friday-wp-production-assets/app/uploads/2025/09/23324976_s-23110042355123.jpg/v/crop-faces:width=256,height=144/format:type=webp?Expires=4102444800&amp;Key-Pair-Id=K2H5GZZHVJCN4V&amp;Signature=VNQyyncEOTTsL5lSDA9VHAj43wa388pnJ64kxfn5vR~eLdecRUQjgqhHH8P~OZQSYetQhbC8hVuTpEYP60RGZIWZ0BkzTA~JjnhAcH7o2U0644Uha6yCBV3gEPq-xpGWzLArTMDzIONmWAHB-x~ZEYhNWKK4Bh1l6uNgUJ6P9oYBYHEz8gwNtBcf2B-OJNquib8q8J16dbWY0S-a7nx6IR832xy2b9AjnlmAxfWVo98bm6a-j0e8j56-~x1YQ3WyOfTvijXLEQeWAnyEhQ52-oWcgNTHvczS8Nl3lGCGDj3pZoAZq6~dqYV38aYk0o-rQXTkMsVlxW9Q2yCZURncrw__" data-friday-gold-link-thumbnail-square="https://assets.friday.gold/friday-wp-production-assets/app/uploads/2025/09/23324976_s-23110042355123.jpg/v/crop-faces:width=105,height=105/format:type=webp?Expires=4102444800&amp;Key-Pair-Id=K2H5GZZHVJCN4V&amp;Signature=HxNAq8c1AbT5~gaIQrC7QVldApYLDT9bEOLJi5Jad8LeJ20EzTqhA8mZJj1o-UicVsMEA0LsYZvmXQEIGuD3hLPUBOhf~IErqD0dZoPp3NSIOYo5fpBZd6ObVcIBe33IhHPKtiwykm9V-E9K3Jy27rmqMnqsXtrLATngMyKS9fnFWDxpFqa-YgCIusxcBG7CuPe~dmkYH~maHX26G~085B~XuGlMA1~XOV-Q-S7Zwnbjp~5Lft-GAHDNb9dyDFkOOoYoteYO2LaAQyFs2jghdzTe14WujdCeO0fPZBwjBKhDb1J8taQADUH6nf~SHr5Hnhjp-pyCsxiDSDd9sN18Fg__"></div>
<p><a href="https://x.com/yhdgj675">■Mr. Tachan’s X (formerly Twitter) “Tachan @Bubble Old Man” is here</a></p>
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<figure id="attachment_439904" class="wp-caption alignnone" style="width: 1000px;" aria-describedby="caption-attachment-439904"><a href="#" data-ident_hash="b2d7029a"><img src="https://res.cloudinary.com/fridaydigital/image/private/t_article_image/wpmedia/2025/09/51494b66b20eaec11fe501f5bdf797f4.jpg" alt=""></a>“I want you to use money to expand the freedom in your life and eliminate your worries about the future.” It was from this desire for his daughters that “Lessons from an Investor Father Who Turned 500,000 Yen into 5 Billion Yen” (Diamond, Inc.) was born.</figure>
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<p><a href="https://amzn.to/4gritRO">■You can purchase Taachan’s book “Lessons from an Investor Father Who Turned 500,000 Yen into 5 Billion Yen” here.</a></p>
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 After working as a money writer, financial planner, and market analyst for a securities company, Matsuoka became independent in 1996. He writes articles on finance and asset management mainly for business and economic magazines. Author of "A Textbook for the First Year of Robo-Advisor Investing" and "Understanding with Rich Illustrations! The Book of Cashless Payments and the Book of Absolute Advantages. X (former Twitter)→@1847mattsuu

 Kenji Matsuoka

 Mr. Ta-chan has built a stock portfolio of more than 5 billion yen by using "value stock investment," which he originally established when he was a university student. He has succeeded in systematizing value stock investment, which is often summarized in one word, based on his practice. What is his "investment technique"?

A Doctor Facing Terminal Cancer Reveals How He Turned ¥500,000 into ¥5 Billion Through Value Stocks

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