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: Michael was stunned to learn he had HIV. Sentence2: He knows it is not a death sentence but was still very upset. Sentence3: He was mainly worried about all of the people he had sex with. Sentence4: They would all need to be told and get tested. Sentence5: He didn't deceive anyone but still felt horrible for it anyway.
A:
Michael