In Shanghai, you can try the following places to buy products related to Ninja Turtles:

1. Toy store: You can go to some large toy stores, such as Big World Toys, Disney Store, Toys R Us and so on. These stores usually have toys for all kinds of anime characters, including Ninja Turtles.

2. anime shop: Some anime shop or bookstores in Shanghai, such as Kebangkok, Dongsen Animation, Mars Times, etc. There will be some animation-related products. You can look for related products of Teenage Ninja Turtles.