The stock was tumbling at the turn of the century, as a new idea - preparing food to order - proved cumbersome.

The company closed old stores, stopped adding new ones, and rejected the menu.

It sold more breakfast food and coffee. It worked.

Then, sales stalled again.

Surely, the age of the burger had passed.

Nope. A new boss and a simplified menu got sales going again,

sparking a sharp rally in the shares in the latter half of last year.

Investors who have stuck with the shares have beaten the S&P 500 by a fat margin.

None of these happy comments apply to McDonald's publicly traded Japanese affiliate, however.

Its sales have fallen in every one of the last seven years.

Sales have been hammered in the last year or two, as one food quality scandal has followed another.

Sales have only just started to recover.

Net profit, which has never been very high, is expected to be barely positive this year.

What part of these struggles is down to Japan's aging population and chronic deflation?

And how much is failure to emanate the competitive agility of its protean parent company?

It's hard to say. But either way, the price investors pay for each dollar of sales at McDonald's Japan is very cheap relative to the parent.

Those who still harbor bullish feelings about Japan, where GDP growth estimates were nudged up this week, should find McDonald's Japan interesting.

Boss, Sarah Casanova, is in the midst of a shake up, hinging on menu tweaks, lower prices, and sprucing up the shops.

McDonald's Japan's nearly 3000 stores is a meaty 8% of the global total,

and the parent company has a 50% equity stake in it.

The parent is considering selling down the stake, but it will not want to do so while the company's value is depressed,

and whether it sells or not, it will not want to see its brand wither in a crucial market.

McDonald's Global, a proven winner across the decades, has good reason to support the Japanese turnaround.

Robert Armstrong, LEX.

Giles, you and I have spoken in the past about how apparent or real volatility in the pound, which is so often associated recently with Brexit, has been a bit exaggerated,

- Yeah. - And we've played it down.