Japanese Marketers are a wildly effective lot. Tissue papers and faaaar too many anthropomorphic things are the basic weapons of war in the advertising toolbox.
Of course, total disregard for any connection between the spirit of your product and the image company it keeps is a good way to stand out. Gyoza are deep fried dumplings, and probably among the least healthy and most fattening snacks to be had in Japan. In other words, they go perfectly with a nice cold can of beer.
English help: anthropomorphic - giving human attributes to everyday things. Like smiley faces on trains and sad faces on furniture.