Detailed 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.
Q: Sentence1: One week a couple received a call from an old friend. Sentence2: The friend planned to be in town and asked to stay with the couple. Sentence3: They spent the week cleaning their home. Sentence4: However, at the last minute the friend said he couldn't make it. Sentence5: They were disappointed but happy that they had a clean house.
A:
Couple, Friend