Marietta Muir is a character appearing in Atelier Ayesha: The Alchemist of Dusk.
Marietta is a store clerk at the Black Cat's Path in Vierzeberg. She constantly worries about her boss Harry, and has taken a lot of responsibility for the store in his place, as Harry is rarely seen working. She takes her job as a trader seriously, and is always looking for business opportunities to improve the store.
Ayesha can buy, sell and register items with Marietta at the Black Cat's Path. Marietta also registers Ayesha into the Treasure Contests. She hosts these contests twice a year. She is seen in a variety of events while Ayesha is staying in Viezerberg.
Marietta is oblivious that Fred Rodfork is in love with her. Fred asks Ayesha to find out what kind of bread Marietta would like to eat during an event, which results in Fred carrying an extended inventory of new bread.
Marietta seems to have set her eyes on Keithgriff Hazeldine, as she seems determined to introduce herself to him and asks Ayesha details about him. Despite the fact that he's much older than her, Marietta claims that it's hard to find hard working and responsible men her own age and prefers an older gentleman.
She believes in treating all customers fairly and has a high sense of integrity. Even when she cannot figure out what her Homunculus customers want when they initially ask for "sparkles", she goes to great lengths to please them, even though Harry insists that she give up. With Ayesha's help, they are able to determine that the Homs are looking for candy, and Marietta is able to make good on her business with the Homs.
Completing the "sparkles" request and helping Marietta out is required for the "Girl's Gathering" ending.