Ameya-yokochō is widely known as the place to pick up bargain kicks; but among running-shoe fans, it's better known as the home of Mita Sneakers, which sells limited-edition made-in-Japan shoes and exclusive collaboration items from the big brands (Adidas, Puma et al).
It has a couple of outlets inside the wedge-shaped Ameyoko Center Building – one outside of the ground floor and another inside on the 2nd floor.