In this task, you're given a story (which contains five sentences only). Your task is to find all the characters which are available in the given story.
Q: Sentence1: Mona went to Paris to study music. Sentence2: When she met her piano teacher, she had a hard time understanding him. Sentence3: She tried to speak in English but he didn't understand her. Sentence4: Eventually, they found a way to communicate with their hands. Sentence5: Until Mona learned enough French to follow her lessons.
A:
Piano teacher, Mona