The Characters of the Story

1. "At the top of a squatty, three-story brick Sue and Johnsy had their studio. "Johnsy" was familiar for Joanna. One was from Maine; the other from California."
The two most important characters of the short story.
Sue is a very kind girl and she loves her friend. She takes care about her.
Joanna is sick and tired of pneumonia. That's why she has thoughts of dying.
2. Mr.Pneumonia. The killer disease which plays so important a role is personified by O.Henry in this short story.
3."The busy doctor" who treats Joanna and "Old Behrman."
4. and lastly, "Old Behrman was a painter who lived on the ground floor beneath them."