I don't think its sales were affected by the demonstrations: it is a well established product and the majority of Chinese consumer don't know that it is a Japanese brand.
The "Japanese" sushis restaurant stopped selling sushis for a few weeks.
They tried to switch food and offer more fried nuddles for instance...
Chinese consumer stopped buying Japanese car during one month.
Now I believe that the sale came back to their initial level.
Hyper-mart, the Chinese Wall-Mart or Carrefour plays the card of the "made in China"! They launched a new strategy just a few days after the end of the demonstration...
In my opinion, this is a real shame to boast the Chinese identity while generating more antagonism, in order to make money and sell more! But no one said anything about it.