Cecilia Helmold is the older sister of Totooria Helmold, the main protagonist of Atelier Totori, and daughter of Guid Helmold. She took over motherly duties of the Helmold household since her mother, a famous Arland adventurer, went missing years ago. Though Cecilia loves Totori, she often worries for her well-being and nags her on what she has been doing. Cecilia also had her arguments with Totori and will scold her for any ideas or actions she thinks is too dangerous for her to partake. After their arguments, Cecilia will often sulk and pout that she's right in the discussion at hand. Though if she see Totori upset over their ordeal, she will make up to her.
Cecilia immediately scolds Totori on her intentions of becoming an adventurer, as she believes their mother, a famous Arland adventurer, is long gone. However, she already knew that Totori wanted to be an adventurer and had her best friend, Melvia Seibel, play into and help Totori in getting her adventurer's license. Once their plan played out, she finally allows Totori to go to Arland to apply for her adventurer's license. During the time when Totori was away, Cecilia was bored sitting around the house and took a job at Gerard's Bar as a cashier and waitress.