This article explores the question of whether Japanese hair is thick or thin and what factors contribute to its thickness. It discusses the two main types of hair in Japan (straight and wavy/curly) as well as its unique structure and texture due to its higher density of cuticles. Genetic factors, environmental factors, and popular hairstyles in Japan are also discussed in relation to the thickness of Japanese hair. On average, Japanese hair tends to be slightly thinner than other races due to its finer diameter shafts, but it has more hairs per square inch which makes up for any apparent lack in individual strand thickness.