Specific Department Store in Tokyo

I knew there are a lot of Department stores in Tokyo: Takashimaya, Mitsukoshi, Matsuya, Matsuzakaya, etc.
Are these department store has specific items that other stores doesn't have? or are they generally selling the same things? For example, if I am looking for children shoes, which of these dept.store has the most collection?

For example, if you're looking for children shoes, all the department stores you've named have them. But some department stores carry certain brands while others don't. You can take a look at the department stores' official websites to get the feel of the uniqueness they hope to aim for.