Best location around Shibuya/Harajuku to take young girls to people watch?
 

My girls are 8 and 10 and love Japanese fashion. We will be in Tokyo next week and I want to take them out on Sunday to gawk at elaborately dressed teens. I know Harajuku used to be a popular place to people watch, but is it still? We live in rural northern Japan, where the fashion isn't as current and I'd really like them to see some memorable fashions. Any suggestions? Where should I go spefically (streets, areas, etc.)? Thanks!