The Heiress's Revenge Diary

Content Warning: This title contains material that may be distressing for some readers.

Yuta, who is attending the best high school in the prefecture, is subjected to extreme bullying by the student council president and their two lackeys. Despite the horrible bullying, Yuta endures it all for his precious younger sister, but they eventually get to her too, "breaking" her. Then one day, a mysterious transfer student, Mirei, comes and says she's going to "start her mission to set society right"?

Original Manga
Official English