He wanted to protect her, just as he did when they were children.
He helped her chase off the bully in the village, telling him that no one could pick on his sister.
He helped her pick sour jujubes from the tree and told her that as her brother, he should be the one doing dangerous things.
He quarreled with the village children for teasing her as an unwanted wild child, stating that she had a family and she was his sister.
Mrs. Xu snapped out of her thoughts and suddenly told her son, "Alright, I won't stop you anymore. You can join the army. As long as you remember that you must bring the young mistress back home in the future, I believe you won't behave recklessly and will follow the rules."
"Mother?" Xu Zhengyong spun around, staring at Mrs. Xu in surprise.