Group 1 - The article discusses the reasons why Japanese people do not commonly eat crayfish, particularly the American crayfish, despite its presence in Japan since the early 20th century [1][21][37] - Japanese native crayfish, known as "Yamato crayfish," is now endangered and protected, making it illegal to catch or consume [3][24] - The introduction of American crayfish in Japan began in 1926 for consumption purposes, but it has not become a staple in Japanese cuisine [4][5][21] Group 2 - The article highlights that while some restaurants offer crayfish, it is not a common dish, and the majority of Japanese people have limited exposure to it [21][22] - The perception of American crayfish includes a strong muddy taste, which contributes to its unpopularity among the Japanese [8][37] - The recent designation of American crayfish as a "conditionally designated alien species" restricts its commercial use, further limiting its availability in the market [24][36] Group 3 - The article notes that the culinary culture in Japan is rich with other seafood options, reducing the necessity for crayfish consumption [37] - There is a small niche market for crayfish among those who have experienced it abroad or are interested in unique ingredients [22][37] - The lack of traditional cooking methods and recipes for crayfish in Japan has hindered its acceptance and popularity [37]