Shadow Lady Vol 1

From the Dark Horse edition

In Gray City, a glorious but crumbling metropolis, a different world exists between night and day. Here we find Aimi Komori, a shy girl with a secret—her magic eyeshadow transforms her into Shadow Lady, an infamous thief who sees Gray City as her own personal playground. Along with her pint-sized, bat-winged sidekick, De-Mo, Shadow Lady turns the menacing metropolis absolutely upside-down!

Source: Anime News Network Encyclopedia