Marie and Ran both should come with alternate versions of their outfits. If you complete Ran's "Too Hot to Handle" sidestory, you get an outfit for her.
ETA: On Dearonnus offical patreon (artist of NBD) they state that 22 total outfits are in the game. Some are color variants of other costumes
2nd ETA/R: Helps the slums people with a hidden character specifically enough times and you'll get an outfit