Akiho Nogizaka

Akiho is Haruka's and Mika's mother. Despite having given birth twice, she appears youthful and beautiful; Yuuto originally thought she was Haruka's older sister or cousin when he first met her. She is a principal of a cooking school. She has a quiet and intellectual demeanor but has the strength to overcome her husband; in fact, she is referred to by Yuuto and Haruka as "Nogizaka house's ultimate weapon." In contrast to her husband, she thinks it is good that Haruka and Yuuto spend time together, and she likes to watch the development of their relationship. However, she is very strict that Haruka keeps up her studies.

(Source: Wikipedia)