Hii was first introduced by Reita who asked for Kusuo's help about her. Hii's first day of transferring to the PK Academy, she was covered in blood and cuts. It was revealed later by Mikoto that Hii has a death sign on her face just like Chisato's father. The three psychic then decided to follow her and is challenge by the surrounding unfortunate accidents caused by Hii. She is so unlucky, it could be considered ESP.

(Source: Saiki Kusuo no Psi-Nan Wikia)