It completely copies the plot and setting of Watchmen—except that everyone has been turned into a magical girl.

Yes, the story and character setups are basically identical. For example, Sweet Berry（the girl with pink dress) is the only magical girl still active after Japan enacted the Magical Girl Prohibition Act in 1997. She is already an adult, but her appearance is frozen at around twelve years old—short in stature, yet fighting in a brutal and highly experienced, almost deranged way. She is known as the “mad dog,” “cop killer,” and “torturer.”

Every other magical girl character can be directly matched to a corresponding Watchmen character, and the overall plot progression is the same as well.

Personally, I think this novel goes far beyond homage or inspiration and falls squarely into outright plagiarism. So I hope people won’t spend money supporting it (it has also been on hiatus for a long time). But it’s still kind of funny to see Japanese artists drawing Rorschach (and everyone else)as a magical girl.

Aside from outright copied works, there are also two other characters that the authors themselves have mentioned in interviews as being inspired by Rorschach. Looking into their stories and personalities is quite interesting too:

Levi ( Attack on Titans )

Sayoko ( Ghostpia )