It’s often referred to as “spicy tuna roll” (close-up view), an “inverted” sushi-roll (“ura-maki” in Japanese) containing a piece of spicy tuna meat and cucumber at the center and decorated with sesame seeds on the outer surface of white sushi-rice layer.
Can you see how Ichiroll is different from the authentic Japanese-style tuna roll “tekka-maki” (鉄火巻, red-hot iron roll)?
1) The location of black “nori” sheet is different: inside in Ichiroll and outside in “tekka-maki”.
2) Sesame seeds are not used in “tekka-maki” at all.
3) “Tekka-maki” does not contain any cucumber: cucumber is used separately to make another authentic sushi roll, cucumber roll (“kappa-maki”, 河童巻 in Japanese).
4) “Tekka-maki” contains green grated wasabi (Japanese horseradish, the first-choice spice in making sushi with fresh fish meat) as the sole spice but Ichiroll does not appear to contain it (not much, if any).
5) The color of tuna meat looks different: Tekka-maki uses sashimi-quality fresh tuna meat (red color), while Ichiroll uses tuna meat flavored with a spicy miso sause containing chili pepper (brownish color).
Besides these visible differences,
6) The black “nori” sheet used in “tekka-maki” has a natural “nori” flavor without particular additional seasoning, while that used in Ichiroll is flavored with sesame oil (a characteristic of Korean-style “nori” sheets).
Thus, Ichiroll is a unique mixture or “alloy” of Japanese (sushi roll containing tuna), American (“inverted” sushi-roll decorated with sesame seeds like California roll), and Korean (chili pepper-flavored miso sause and sesame-oil-flavored “nori” sheet) food cultures impossible in no place other than the West Coast area of North American continent. While reactions of Safeco Field visitors from Japan to Ichiroll is controversial (mostly negative), this is indeed an interesting example of exported Japanese culture. How can we Japanese ban Ichiroll sold at Safeco Field SIMPLY because it is not an “authentic” Japanese-style sushi? Importing foreign (food) culture and arranging it to fit in with the existing life style or specific needs have been historical habits of Japanese.
APPENDIX: The authentic “tekka-maki” has one advantage over Ichiroll. You can eat as many “tekka-maki” rolls as you like with your hand, without using chopsticks, and then get back to work without washing or wiping your finger tips. No fear of soiling paper documents or computer keyboards with greasy or sticky fingers. An ideal take-out lunch menu for busy office workers.