Mike
Mike is the protagonist of The Moustache and goes to visit his grandmother. When there, she mistakes him for her late husband and begins a conversation about regrets and her last argument with him.
Mike's mother
Mike's mother is introduced at the beginning of the story and is said to have a great relationship with her son. She doesn't like Mike's moustache as she believes a seventeen-year-old should not have one.
Mike's grandmother
Mike's grandmother accidentally mistakes Mike for his late grandfather and begins telling him about her regrets. Mike learns a lot about his grandmother and sees her in a different light.
Howie
Howie is a divorced father who sees his daughter Holly every Thursday. However, he must learn to be a better and more reliable father if he is to continue seeing his daughter.
Holly
Holly is Howie's daughter and has a strained relationship with her father as he left when she was young. Even today, he continues to be immature and unreliable, leading her mother to cancel their visits.