Noroi no Tegami

The protagonist, Naoe Nagahisa, had lost his younger sister and was climbing a mountain with the intent of following her into death. At the top of the mountain, on a hill offering a panoramic view of the sea, Nagahisa meets a mysterious girl named Ichijou Hiiro. As he became more deeply involved with Hiiro, Nagahisa eventually discovered that she was, in truth, a sorceress. This is a short story woven from the threads of love and curses. [Translated from Novelgame]