He's not wrong. TEPCO (the builder/operator of the Fukushima plant) and NISA (the Nuclear Regulatory Commission equivalent in Japan) made mistakes for decades. And they didn't stop when the disaster happened. But there are more impartial, more accurate places to get this information. Mr. Takashi, whom I understand is a musician and chef by training, is so wrapped up in his anti-nuclear rhetoric that the entirety of the book read like an angry rant written by an anonymous internet user typing in all caps. He makes a big to do about the fact that all these reactors are designed to do is boil water, how silly of us, we could boil water another way! As if there aren't environmental and economic consequences to other types of energy production. Japan is a small group of islands, they don't exactly have the resources the US does. And he loses IQ points by the minute when he declares that if reactors were safe, why don't they put them in populated areas, specifically the center of the city of Tokyo! Well, I have been to several of the larger cities in Japan, Tokyo included, and they don't have room for all of their own city residents, much less a large complex of nuclear reactors (I defy Mr. Takashi to find the money to pay for all of that eye gougingly expensive Tokyo real estate). With most writers, you'd just call all of that nonsense hyperbole, but with Mr. Takashi, it seems like he is actually using that as a logical argument. He also can't see the forest for the trees, focusing intently on whether the earthquake was 8.4 or 8.8 or accurately upgraded to 9, when the list of TEPCO's hamhanded management and outright safety violations are mere footnotes, if discussed at all. NISA's lack of accountability and willful ignorance should have been covered more in depth too.
And Mr. Takashi's understanding of radiation science - dosimetry, dispersal, and decay - is poor. He starts his chapter on the effects of nuclear radiation on living organisms by saying that he's not going to use standard metrics or even numbers as a measurement tool, or any unit of measure at all, simply because radioactive decay does not leave the area completely free of radiation, it will only breakdown into an amount infinitesimally close to zero. He makes it clear that even one atom that is radioactive is so dangerous that any use of radiation metrics as a means to understand the impact of radiation on people should simply be thrown out the window. His understanding of the actual effect of radiation on humans just deteriorates from there. And of course, you won't be able miss the giant I TOLD YOU SO draped all over the text.
In the end, it doesn't matter. The book was written 6 weeks after the disaster, and much has happened since then. There are better, more thorough discussions of the tragedy. The best I have found is actually Wikipedia. Now we all know that Wikipedia has impartiality and inaccuracy flaws inherent to their system, but it's quite a step up from Mr. Takashi's work. It is up to date and extremely thorough - you'll gain a lay understanding of the nuclear physics of boiling water reactors, if you haven't already got one. It discusses the impact of radiation on people - and ecosystems - based on actual radiation biology - no "to hell with the numbers" here. And I'm sure to Mr. Takashi's relief, it does NOT leave TEPCO and NISA off the hook. Much like as was the case with the Chernobyl and Mayak disasters, sometimes the western press, with its 100% free press and aggressive investigative journalism, gets the clearer picture of the disaster at hand.
So in summary: Fukushima was a monumental disaster and a tragedy beyond measure, but Mr. Takashi is not the person you want explaining it to you.