Isekai Tensei Shitara Dai Mahoutsukai no Oshi ni Narimashita

The main character, who was an ordinary office worker, was gifted a powerful magic by God (?) and was reincarnated in another world. The main character, who has become an 18-year-old village girl, activates a great amount of magic and faints in order to save a man who was about to be attacked by a beast in the forest. When she woke up, the man she helped suddenly confessed to her...!