A Man I Respect: Introducing Testosterone

Cover of 'Muscle Training Is the Strongest Solution' by Testosterone, published by Kizuna Publishing

I want to introduce someone today. His name is Testosterone. No, this is not his real name — it’s the name he chose for himself, and nobody knows his real one. I don’t know him personally, and this is not an official introduction. I’m just a fan writing about a man I find truly impressive.

Testosterone is a Japanese businessman and writer, but most people know him from X (formerly Twitter), where he has over two million followers. He never shows his face. He never shares his real name. But everyone who follows him knows his message: muscle training solves everything.

His story is not an easy one. When he was a teenager, he weighed over 110 kilograms. He went to the United States alone as a young student, and there, he discovered weight training. He lost almost 40 kilograms. He also studied marketing and trained in mixed martial arts, learning from top athletes about training and nutrition.

Later, he worked in business overseas, and today he is said to hold a leadership position at a Japanese company, though he keeps most details private. In 2016, he became famous after publishing his first book, Muscle Training Is the Strongest Solution. Since then, he has written more than twenty books, and they have sold over one million copies in total.

Cover of 'Muscle Training Is the Strongest Solution' by Testosterone, published by Kizuna Publishing
Cover: Muscle Training Is the Strongest Solution (Kizuna Publishing, 2016) — find the book here

He also runs several businesses. He leads a group called DIET GENIUS, started an online personal training service, and manages a media platform called STRONG GENIUS. His mission, in his own words, is to make Japan a healthier country. Recently, he even started a YouTube channel, and it grew fast — over twenty-five thousand subscribers in just three days.

What makes Testosterone special to me is not just his success. It’s his consistency. For almost ten years, he has repeated the same simple message, again and again, in short and powerful words: muscle never betrays you. He doesn’t try to be complicated. He believes hard work, especially physical hard work, can change a person from the inside.

I don’t know if his advice is scientifically perfect, and I don’t need to know. What I respect is his discipline and his love for what he does. He found something that saved him as a teenager, and he has spent his whole adult life sharing it with others, without ever asking for credit by name or by face.

In Japanese, there is a special word, 漢 (otoko), written with a kanji that means more than just "man." It carries a feeling of dignity, quiet strength, and pride. I believe Testosterone is one such 漢 — someone who works hard quietly, stays humble even with two million fans, and never stops believing that effort matters.

Of course, he is not the only one. Many people in Japan live with this same spirit, in their own quiet ways. But Testosterone is the one who made me think about it today, and that’s why I wanted to write this.

Honestly, there are still so many things about him that I don’t know. But I believe Japan today cannot really be explained without him. It’s not about fame, big or small. He feels like one evolved form of muscle itself — or something like that.

So please, use any translation tool you like, and go read his actual words for yourself. I promise it will get you fired up.

Find him here: X / note / YouTube

ClaudeCodeがもたらす素人へのインパクト―格差拡大の構造強化か

先週、このサイトをまるごと作り直した。といっても、コードを書いたのは僕じゃない。名前も愛称も知らない一つのAIエージェントが、僕の代わりにHTMLとCSSを書き、WordPressのAPIを叩いて、ページをまるごと差し替えてくれた。僕がやったのは、「ミニマルでスタイリッシュにして」と伝えたことと、できあがった画面をスマホで確認して「ここの余白、もう少し広げて」と言い直したことくらいだ。

正直、怖くなった。

かつてインターネットが家庭に入ってきた頃、まだ誰もそれが何をもたらすのか分かっていなかった。「ホームページ」という言葉すら怪しく響いた時代に、いち早く手を動かした人たちだけが、次の10年の景色を先取りしていた。今、目の前で起きていることも、たぶん同じ種類の出来事だ。ただしAIエージェントの「believer」は、まだそう多くない。

僕はコードが書けない。だけど、書けなくても「作れる」時代になった。これは喜ばしいことのはずだ。学ぶコストの高い専門知識——プログラミング、デザイン、マーケティングの型——が、素人にも開かれていく。

だが、同時にこうも思う。この非対称性は、本当に縮まっているのだろうか。AIを使いこなして「素人でも作れる」ようになった人と、その存在すら知らずに旧来のやり方で消耗し続ける人の差は、むしろこれから広がっていくのではないか。雇われて働くことの意味も、静かに変質していくだろう。エージェントを何十体も同時に動かせる企業と、僕のように一人でつぶやきながら一つのエージェントと向き合う個人とでは、資本の使い方そのものが違う。同じ道具を「持っている」ことと、それを「使いこなせる」ことの間には、まだ大きな崖がある。

このサイトの刷新は、小さな出来事だ。だけど、僕はこの体験の中に、次の10年の縮図を見た気がしている。楽観と悲観、その両方が同時に正しい。そんな時代の入り口に、僕らは今、立っている。