Aika Denji, the SHSL Balneologist, which is the study of baths, bathing, and how disease is related to it.  Aika's voice I imagine is slightly deep, smooth and seductive! 

Aika lives in a small home with her brother. Her mother works in the city, in an effort to preserve what she had left. Her mother took on a special job at the local pub so she could provide for her children. Now, Aika had always looked up to her mother and was taught all the wrong things at a wrong age for very wrong reasons. However, once in while, happiness did fall upon the family. For the children, at least. They would gather in the family hot springs, Aika, her brother, her mother, and her mother's latest catch. Funny enough, she never witnessed anything, or at least so she claims. Denji is very reluctant to talk about her past...