Is China really rising yen?

Recently, some analysts have argued that yen is appreciating because China is buying it. Let's see some example. Marshall Auerback said;

The best means of avenging the nation for historical slights and grievance, and making oneself the dominant power in Asia (whilst mitigating the influence of the US through its levers on Japan) is very simple: just buy yen and force the Japanese corporations to hollow out Japan.

China's intention is clear, according to Auerback. He reiterates;

And what does this mean for Japan, which is the canary in the coal mine? With this kind of investment going on in China, the Japanese firms haven't a chance to compete with the yen prevailing at this level. And China knows this so it continues to buy Japanese yen bonds, which keeps the currency high and basically destroys its main Asian competitor. It represents the ultimate revenge for Manchukuo and the Rape of Nanking. And this is a development that could move very fast because the excesses of investment in China are currently so great.

Historical reason. Yeah. It's easy to understand. Yves Smith joins the forces.

Hefty buying by China has pushed the yen to high levels which are particularly damaging to its economy

But we know that China sold Japanese bonds in August. According to Japan's Ministry of Finance,

Data released Friday by Japan’s Ministry of Finance showed China sold a net ¥2.018 trillion ($25.59 billion) worth of Japanese assets in August, selling back most of the net ¥583 billion it bought in July and the ¥2.3 trillion it bought in the first half of the year.

It means that in August, China sold about 90% of Japanese bonds it bought this year. If China is a culprit of yen appreciation, yen should have depreciated in August given that China sold its yen holdings. But wait! Yen appreciated in August, didn't it? Japanese bonds markets also rose in August.

The graph above shows the US dollar/yen trend from July to October. It's clear that yen APPRECIATED in August, not depreciated. So, the question should be: Is China really the driver of yen appreciation? We have to come back to that question rather frequently.