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: Lisa had a relationship of five months with Troy. Sentence2: Her sister was her best friend and was eager to meet him. Sentence3: When her sister met Troy, she gave him the third degree. Sentence4: He was confident, nice and stood his ground. Sentence5: Lisa's sister was very pleased with him and gave her the green light.
A:
Lisa, Troy, Her sister