Mamiya Haruna

What she calls the protagonist: Ryou-chan

The quintuplets' mother who has a kind personality. She is always seen with a smile on her face, and is a good wife as well. Haruna supports her husband from the shadows by taking up the role as Seamore's manager.

Because of her young appearance, she is often though to be the quintuplets' older sister instead of mother. Haruna loves her children very much and is always giving the girls consultation - whether it be about love or other matters.