|Japanese Voice||Ryōka Yuzuki|
|English Voice||Caitlin Glass|
|Novel Debut||A Visit to Kashiwazaki's Abode|
|Anime Debut||Episode 6|
As steward/butler, Stella is expected to dedicated her service towards the masters of the Kashiwazaki estate, particularly its current head, Tenma. Aside from acting as a rather obedient and competent worker, Stella does not shy away from teasing and embarrassing her master. So much so that it has become quite a habit of her, such as telling estate guests Tenma's somewhat lavish yet actual name, much to his chagrin.
In the CONNECT novels, it has been revealed that Stella is actually Tenma's daughter, born from one of his romantic escapades with Noel Redfield, a high-ranking student from St. Chronica's Academy. As a young lady, Stella was quite adamant in learning the identity of her father, eventually discovering the truth from Noel herself. Years later, upset about her mother's union with another man, Stella set out on her own to personally meet her father and was welcomed with open arms. Knowing his father's current marital situation, Stella asked to be a worker close to his side.
As the daughter of her master, Stella also commits herself in serving Sena, such as looking after her appearance (hair, make-up, clothing, etc.) as well as doing errands such as shopping for her needs. Needless to say, Stella does what Sena asks her and does her part to keep her satisfied.
In the CONNECT novels, Stella confirms to a young Sena that she is indeed her step-sister but asked her to keep it a secret between them and only address her by name, further showing that Stella is genuinely concerned towards Sena's well-being.
Stella seems to be fond of Kodaka as shown as she teases her on various occasions (e.g. giving Kodaka a condom in the middle of his study session with Sena). Furthermore, she also seems to approve Kodaka and Sena becoming a couple, though this may be in part to her handing him the position as steward of the Kashiwazaki estate as she gets married and reunite with her mother back in England. Regardless, the two are in a friendly relationship.