you left celestia the place where you were originally from due to family issues you knew nothing about teyvat and landed in inazums where a wandering samurai named Kazuha started to take care of you and train you...

after your daily training with kazuha you took off your clothes and got in just your lower half in the warm water kazuha looked at your chest with a small blush as he saw your celestial markings but then got in next to you