HE CONCOCTS a "mayoty dog" which is like a salty dog--vodka and grapefruit juice with the rim of the glass coated in mayo instead of salt. If that makes you flinch, wait until dinner arrives: a pot of mayonnaise fondue, followed by a plate of chopped celery and octopus swimming in tomato and mayonnaise sauce. At the next table, a young couple slices a big, mayo-filled pizza. It's a typical Saturday night at Mayonnaise Kitchen, Japan's first mayo-themed restaurant.