Yamada-kun and the Seven Witches (2015)

S01E10 Please Go Out With Me

In their quest to locate the elusive seventh witch, the Supernatural Studies Club encounters Leona, Miyamura's sister. She has left school to break free from the witch's ability to wipe memories. The moment someone discovers her name, they risk losing all recollections connected to witches, putting everyone in a precarious situation.