Aer is a young woman wearing a waitress like uniform.
Aer first appears after Touya, Linze and Elze had completed their first Guild mission. She was introduced by Micah and wanted to have something new added to the Parent cafe's menu. She asked the group if they had any ideas or had tasted anything exotic.
Touya suggested ice cream, not knowing that it didn't exist in this world. After looking up a recipe with his Smartphone, he managed to make a batch with the ingredients and Linze's ice magic. The introduction of ice cream, and later the Roll Cake, soon made the Parent Cafe widely popular.