A young girl who is training to be in the Olympics for shooting sports could be a main character. She spends most of her time at the Castle Shooting Range, perfecting her aim and dealing with the pressure of competition. There could also be her coach, who is like a strict but loving father figure to her, constantly pushing her to do better.
Maybe a group of friends who are all into shooting as a hobby. They have different personalities. One could be the daredevil who always tries the most difficult shooting stunts, another could be the cautious one who makes sure everyone follows safety procedures at the Castle Shooting Range. And they all have their own dreams and goals related to shooting, which form the basis of the story.