Charlotte is a major character in the game and one of the protagonist's only contacts on mars world.
Meet lonely Charlotte - an unlikely survivor who is one of the few remaining to remain after a deadly virus wipes out nearly all of the human population.
Stranded and isolated from the world in her shop, Charlotte has managed to keep both Doctor Money's disease and cure at bay, never needing to leave as she had plenty to eat and drink in her shop.
Earlier in the game, the protagonist will receive an ornate, pink-colored letter, which sender is later revealed to be a woman named Charlotte. She is quite friendly, and she owns a pastry shop named "Charlotte's Delicious Pastries." Although she openly and continually expresses her loneliness to the protagonist, she tries to convince herself that there is a person left in this world besides her
About halfway through, she pulls out a gramophone and plays french-sounding music loud enough that it can be heard by the player.
At some point in the story, she sends you a homemade cake that can be eaten, along with a curious-looking poster that resembles a monochrome heart.
As the game comes to an end, Charlotte requests for the protagonist to "come down here," as she is suffering from loneliness. She also implies that should he not come by "tomorrow evening" (Day 5, game-wise), she will kill herself. She does so later on, right before the player escapes, and writes a final letter for the protagonist to find in her pastry shop should he choose to leave his cell.