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: Sam heard that the school bully was after him. Sentence2: He took a different route home that day. Sentence3: Just before he got to his house, the bully came out of an alley. Sentence4: He began pushing Sam, calling him names. Sentence5: Sam's older brother came by and chased the bully off.
Bully, Sam, Brother