This is the story of Xia Qing, a university graduate just starting out in the working world, whose original name was something else. Years ago, while still in high school, he unexpectedly discovered that he could transform into a magical girl. He used this power to fight enemies from another world. When the war ended and the city began to rebuild, he returned to his ordinary life. But fate wasn't done with him. One day, as he was heading to work as usual, he suddenly learned that he had acquired a new, official identity: the magical girl Xia Kexin.
A decent magical girl novel, you can look forward to the follow-up
It's quite satisfactory, the details are well drawn, and it gives some encouragement.