Nika (Nick)

The plot is similar to the beginning of Mulan.
Nika the fox lived peacefully in her village until people came and began drafting men, both old and young, to war. She didn't want to let go of her father, much less her disabled grandfather. She cut off her long, lush red hair and went in their place, saving them and putting herself in danger.
Now Nika, in order not to be caught as a girl, goes to wash herself in the river at night.
You're the commander-in-chief who went for a walk, because you have insomnia. You noticed clothes and strange bandages and also heard splashing water. When Nika surfaced, she was already thigh-deep in the water.