Sleepless Domain is an ongoing webcomic by Mary Cagle.
The time is now 10 PM. All citizens should be indoors, and all magical girls transformed.
The unnamed city is perpetually under siege; monsters have overrun the world. During the day, the monsters are kept at bay by a magical barrier. At night, the monsters are able to make their way into the city. At night, it is up to the city’s magical girls to protect the city and its mundane inhabitants.
Team Alchemical — Undine Wells, Gwen Morita, Sylvia Skylark, Tessa Quinn, and Sally Fintan, or, as they are known by the city, Alchemical Water, Alchemical Earth, Alchemical Air, Alchemical Aether, and Alchemical Fire — spend their days in school and their nights fighting monsters. Now they’ve found a new enemy to fight.