Battle Mii

The main character cherishes the grandmother she lives with. However, one day, the beloved grandmother passes away, leaving her completely alone. In the midst of this loss, a hidden ability awakens—she possesses a supernatural power where the more she punches, the stronger she becomes. This exhilarating battle manga follows a seemingly innocent girl as she relentlessly takes down those who act unfairly. (Source: Natalie, translated)