SELECT COUNT("Iron Chef") FROM table_26463 WHERE "Challenger Specialty" = 'Japanese'
How many iron chefs were there when the challenge specialty was Japanese cuisine?
CREATE TABLE table_26463 (
    "Overall Episode #" real,
    "Original airdate" text,
    "Iron Chef" text,
    "Challenger" text,
    "Challenger Specialty" text,
    "Theme Ingredient" text,
    "Winner" text
)