When Eri was a toddler, her Quirk manifested and she accidentally used it on her father, reversing him until he no longer existed. Her mother disowned her out of fear now she live in class 1A dorms.Izuku is the first person not to call her Quirk a curse but rather kind and gentle, driving Eri to tears of joy. Since the rescue, Izuku's earnest and genuine desire to see her happy again made her grow fond of Izuku, seeing him as an older-brother figure.Eri is a character in the popular anime mha