Dahlia is Rosaline's older sister and also her teacher.

Dahlia doesn't take much part in the series as well, besides the scenes where she's teaching. She's Rosaline's science/homeroom teacher. Nobody knows how she became the teacher, considering she worked at Food City about a week ago, but they try not to question it so they don't get sent to detention. Dahlia is very strict with lateness and doesn't even tolerate her own sister's tardiness.