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: I turned twenty years old. Sentence2: My girlfriend didn't realize it was my birthday. Sentence3: I tried to drop hints but she didn't get the message. Sentence4: Then I shouted at her for not remembering my birthday. Sentence5: I realized she was not worth the time so I dumped her.
I (myself), Girlfriend