Madame Papillon was pretty accurate on a lot of observations. There is a definite tie in Japan between cuteness and childhood, and childhood and escapism.
Cute is certainly associated with children in Japan, and this is a concept that is also common in the States. Stuffed animals, cartoon themed clothes, bright colors, and a penchant for the adorable constitute the core of many products designed and marketed for children.
In Japan, it could be stated that there is a more formal break between the cuteness of childhood and the responsibilities of adulthood. If you consider the seijin shiki (Coming of Adulthood Ceremony) as an example, we can see several formal and ritualized transitions in Japanese culture that mark the shift from childhood to adulthood. While turning 18 or even 21 in the States hold similar importance in the States, the overall shift is less formalized. In the States, the expectation to give up childhood things to move into adulthood may exist, but it would seem to exist as a less definite expectation.
And, so, in Japan, where cute things are more rigidly assigned to childhood, indulging in cute items can be seen as a means of artificially extending one's childhood. And, as Madame Papillon so excellently pointed out, with the demands and pressures of adulthood, it can be well understood why someone would want to leave adulthood and escape to childhood, even if vicariously through consumer products.
I honestly believe this is not so different in the States, though men may certainly face heavy social pressure to NOT feel nostalgic about cute things, and instead may channel their reminiscences of childhood into more "acceptable" avenues, such as sports. Still, bobble-head dolls can be pretty darn cute . . .
