Finea

フィネア

She is Eneus's younger sister. Although they are not related by blood, their bond was close, like that of sisters, while Eneus spent time in the Demon Realm.
She 'shipped' herself via Postage into the Magical Academy with the aim of freeing her sister from Professor Sakuma, but the reality turned out to be the exact opposite of her expectations.
Ultimately, she was sent to the Demon Realm by her own sister.