The four remaining chefs board an American Airlines flight and travel to Tokyo, Japan. The chefs begin a culinary adventure into the world of umami (a Japanese term for 'delicious' that is used to describe the fifth taste). First the chefs arrive at a traditional Japanese yakitori grill restaurant where they are asked to use Kikkoman soy sauce to infuse umami into their dishes and enhance the flavor profiles of a variety of ingredients. Iron Chef Masaharu Morimoto arrives as a surprise judge for this test. Then the chefs travel through Tokyo to the most renowned culinary academy in the city where they meet Dr. Yukio Hattori, the original Iron Chef Japanese culinary commentator. Dr. Hattori opens the doors to his academy where the chefs are challenged to use different cooking styles in a test that highlights the five tastes: sweet, salty, sour, bitter, and umami. The next chef is eliminated.

The final three chefs undergo a test of Integrity, and how they can honor both personal integrity and integrity of ingredients. At the most famous fish market in the world, Tokyo's Tsukiji fish market, the chefs race to gather ingredients to prepare their version of the most revered and traditional Japanese meal known as kaiseki. This kaiseki meal is filtered through each chef’s unique culinary personality. This traditional Japanese cooking style consists of an elaborately choreographed tasting menu with extreme attention focused on the beauty of each plate and the seasonality of the ingredients. One chef is eliminated, and the last two standing prepare for the final battle in Kitchen Stadium.