>>2456912The story would almost be a normal Magical Girl anime, just will a few caveats.
Magical Familiars (name pending), who appear as an assortment of cute animal like beings (very much inspired by Kyubey) contract girls to be Magical Girls. Events on Earth affect the spirit world, so the spirit world has sent various beings to keep negative emotions in check. All of them have failed and after the disaster of the two world wars, the newest Earthy administrators are very determined to succeed. They do care about the girls, but a combination of their own lack of understanding social hangups and pressure from the spirit world means they sort of see Magical Girls as prized test subjects instead of people.
Magical Girls are contractually obligated to fulfill their duties or they will lose their Magical Girl status. To do this they have to collect a number of Emots from the monsters they defeat (yes, the familiars introduced capitalism with all of it's possible exploitation). Emots can also be accepted from other Magical Girls or from participating in experiments. If a Magical Girls costume get's damaged too badly it coast Emots to repair.
Being a Magical Girl comes with many benefits including enhanced looks, health, ect, and often the girls identity gets wrapped around being a Magical Girl. There are adult Magical Girls, though they are rare due to the difficulty of balancing adult life with their Magical Girl duties.