Ada Vessalius  

, エイダ ベザリウス

Ozz's younger sister loves him deeply. After 10 years, she enrolls at the esteemed Latowidge School for Nobles, where she serves as a prefect. Despite being away from her brother, they maintain communication through letters. Recently, she wrote to Oz and his companions that she has met someone special, prompting them to sneak into Latowidge to meet this person.