Q: 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.
Sentence1: Casey was swimming with some friends at the lake. Sentence2: They spotted a little cliff and decided to jump. Sentence3: Casey was really afraid of the height. Sentence4: She almost decided not to jump, but a boy she liked cheered her on. Sentence5: She decided to go for it and ended up having a lot of fun.
A:
Casey, Boy, Friends