Boba
The base idea is that magic originated from five elemental spirits in the present day the powers of these five spirits can be used by the guardians (prototype name) which basically have the power of the element inside them and can use them to protect the land basically like police but in magical girl form. There can only be five of them at a time and if they have kids then the power is inherited by the first born.
While normal citizens can do magic most of the most common spells are made to make daily life easier such as telepathy and adding magic to medicine. Despite this there are some spells that can be used for combat but most people who know them are in a field of work where it's necessary. Magic can also manifest in specialized abilities that can't be learnt but people are born with and are usually pretty specific in what they can and can't do. How much magic you can do in general is determined by your magical resistance which is basically how close your connection with magic is. For example if you live in the central city were magic is used often you will have a higher magical resistance and can do more powerful spells with it draining your energy less but if you live in a more industrial town or were people don't use magic often you won't be able to do that many spells until you reach your limit this varies from person. Going past your limit can be dangerous as it is possible to overload and basically have the magic destroy you from the inside out killing you. And gaurdians can't use magic onnly their elemental abilities while normal people can't use elemental abilities.
Sorry this was so long
