Nina is a rather timid child, being rather frightened of strangers and very attached to her older brother, Eugene.

Spoiler

Nina's family were minor nobility of Giadian Empire. After the revolution, however, they were stripped of their social status and tax privileges. Unfortunately, as a result of lacking the assets to support themselves like higher nobles and struggling to find work due to the middle class's loathing toward nobles, the Rantz family ended up even poorer than normal laborers. Nina's older brother, Eugene, eventually had to resort to joining to military just to get the funds to support her education. Nina herself was very attached to Eugene, causing her to dislike him leaving her with their aunt while he was on duty.