When Duke Bastella is with Neria, he can forget all of his worries. Even his anxiety and fear when he received an injury that makes him feel weak and useless. Because of that injury, Duke Bastella had to stop being a knight and gave up his position as a General. Everyone pitied him about it, but Neria is the only one who truly understands what he really feels.
Neria stayed with him. She also gave her full understanding and comforted him. She did not leave him and helped him until his full recovery. And during those days, Duke Bastella's feelings for her become stronger. And at that time, the duke was very sure that she is the woman he wants to marry.