Is the Japanese emperor forbidden from eating fugu (puffer fish)?

Question

According to Wikipedia

Fugu is also the only food the Emperor of Japan is forbidden to eat, for his safety

This information comes from a Forbes article "Killer Foods":

The fish remains the only delicacy denied the emperor – too risky.

This seems a bit fishy to me, so doing a search in Japanese, the best I could come up with was this anecdote, with my translation interspersed:

昭和天皇が自分だけフグ食べさせてもらえなくて拗ねられた話大好き。
I love this story about Hirohito sulking because he alone couldn't eat fugu
侍従「陛下はだめです」
Chamberlain: Your Majesty is forbidden
陛下「なんで」
Hirohito: Why?
侍従「毒があるので」
C: It's poisonous
陛下「みんな食べてるじゃん」
H: But everyone else is eating it
侍従「毒抜きしましたので」
C: The poison has been removed
陛下「じゃあ私も」
H: OK, I'll have some too
侍従「だめです」
C: It's forbidden
陛下「なんで」
H: Why?

Here is another page (with a horrendous Google Translate) that makes similar statements.

So, what is the truth about the emperor and fugu?

Answer 1

Formerly the emperors had to stay in their palace in Kyoto and did not have the chance to visit Shimonoseki, where most fugu is prepared. More concretely, fugu was illegal in Kyoto and Tokyo from about 1600 to about 1945. It's fairly probable that no emperor before Hirohito was given the option. (source)

In 1964, Hirohito went to Shimonoseki, but his doctor forbid him from eating fugu, which made him upset. At another time, his son presented him with fugu. Again his doctor intervened and this time Hirohito argued about it for a long time, possibly around two hours, since it was a gift being offered to him. In the end, his wife the empress got him to calm down. Hirohito was never permitted to eat fugu. (source)

This custom has simply changed in the present day. The current Emperor Emeritus (Hirohito's son) was brought up occasionally eating non-Japanese food so got in the habit of choosing his own menu. He has never picked fugu himself, but Shimonoseki City was aware of his broader diet and offered him fugu as a gift, and he was allowed to eat it, so we can say the custom has changed. (source)

Presumably the present emperor eats fugu as well.

Answer 2

I've found references to Fugu (or poisonous Blowfish) being forbidden "to the Emperor", "the Emperor and his family", "to the Emperor and the Empress", To the Emperor and the royal family" in Forbes, NYMag, The Guardian, Chicago Tribune, etc etc.

In this article in the LA Times, they talk about it being an ancient law forbidding the Emperor to eat fugu;

The blowfish, known here as fugu, carries a deadly neurotoxin with no known antidote. An average-sized fugu is chock-full of the poison tetrodotoxin -- in its blood, liver and even its sex organs, Sasaki says.

But he scoffs at the centuries-old ban on the Japanese monarch eating the delicacy, sought after by many Japanese as daring cuisine.

"The prince and other royalty have eaten fugu, so why not the emperor?" he says. "It would set a good example."

Frankly I've seen so many re-hashings of the same phrase (all without any shred of sourcing) that I'm utterly convinced that this is an urban myth, potentially one taught to qualified fugu chefs during their training since they seem to be taken in by it as well.