To add to what Nakiame said: You get a matching C rank outfit by ex clearing the C rank DL live, and another copy of the same costume by ex clearing the B rank live. Then by ex clearing the A rank, you get a matching S rank costume.
Oh, I see. I think I might of misunderstood something. Whenever, I look at the costume type for any live in general, I try to find a costume that matches that type so that I get the smile face. So, that part makes sense.
However, for DL live #1 and #4 I saw the required costume type for their respective live, and none of my outfits matched that type that was listed. So, I thought this was some new costume type that I never got. But, if that's not the case, then the required costume "type" you need to use is the actual costume you receive from rank C version of that DL live? Meaning, use this specific costume only.
So, costumes that have the colored shopping carts are the DL Live outfits?
Sorry, if I sound confused. I hope I understood everything correctly.