Given the task definition and input, reply with output. 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: One day, I was looking through my teenage son's school papers. Sentence2: I noticed a folded paper with my son's name on it. Sentence3: I turned it over and noticed that my son had written about me. Sentence4: He said really kind things, that made me very happy. Sentence5: When I asked, he said that he had to write about his hero.
I (myself), Teenage son