NOTES:
If you don't have Japanese mayonnaise then take about a cup of mayonnaise and add 1 tablespoon rice wine vinegar, 1 teaspoon sugar, 1/2 teaspoon Sriracha sauce and 1 teaspoon dijon mustard.
I found the Schichimi Togarashi at World Market and also Central Market; Whole Foods probably carries it also.
If you want to try and make the spice, here is what I did the first time - For the schichimi togarashi I looked up the ingredients and had almost all of them and simply put them in my motar and pestle and ground them. I had the ginger, sesame seeds, schezuan peppercorn, crushed red pepper and used just those spices (about 1/2 tsp. each). I used about 1/2 teaspoon of this mixture in the mayonnaise and then sprinkled some on top of the mayonnaise.