user: Question: How many iron chefs were there when the challenge specialty was Japanese cuisine?
Columns: ['Overall Episode #', 'Original airdate', 'Iron Chef', 'Challenger', 'Challenger Specialty', 'Theme Ingredient', 'Winner']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'October 10, 1993', 'Yutaka Ishinabe', 'Takeshi Maruyama (丸山\u3000剛)', 'Chinese ( Cantonese )', 'Salmon', 'Yutaka Ishinabe']
SQL:

assistant: SELECT COUNT("Iron Chef") FROM "Table" WHERE "Challenger Specialty" = 'Japanese';