If you're looking for manga similar to Original Chronicle Magical Girl Lyrical Nanoha The 1st, you might like these titles.
I met a Mahou Shoujo; and so began my story. "Then I will become a Mahou Shoujo!" In order to save Hoshi Karen, the Mahou Shoujo who had protected her even while being pursued by tanks. Kokone, who was entrusted with Karen's Grimoire, decides to become that which is acknowledged as a "Calamity" by the world... a Mahou Shoujo!
Rumors have spread of a Magical Girl with the ability to cancel death. To confirm these rumors, the Land of Magic sends two Magical Girls to investigate. What they found instead was a large dome-like barrier. Inside were a group of Magical Girls, calling themselves The Resistance. They claim to fight against what they believe is the corrupted regime of the Land of Magic. As the Land of Magic loses contact with their two agents, tensions escalate as both sides are locked in a clash within F-City.
Subaru is a young girl who discovers that her best friend Aoi is part of magical group trying to gather engine fragments so that a little being from Pleiades star system can return to his home. Subaru considers joining them as she was chosen by the Pleiadian, president of this afterschool club.
Alien parasites have invaded earth, infecting businessmen, and making them turn into... swim-goggle and speedo-clad giants destroying everything in their path? Not exactly your standard magical idol story!
Yuzuka Hanami is a young girl who has few friends but who can do anything. One day, Yuzuka gets accosted by a strange creature named Miton who is digging through a trash dump. Miton tells Yuzuka, "you have the makings of a magical girl" and seems extremely suspicious. When Yuzuka is suddenly transformed into a magical girl, she's wearing a bathing suit.