Instructions: 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.
Input: Sentence1: Yui wanted to join a school club. Sentence2: She couldn't decide which club to join. Sentence3: Her friend told her that the music club was fun. Sentence4: Yui decided to join them because she could play guitar. Sentence5: The club had a spot open and they happily made her a member.
Output:
Yui, Music club, Friend