The Ancient Magus' Bride: Midsummer Pilgrimage

A non-human, living alone in the night of London. One evening, he meets a girl seeking help in the fog. She has lost her memories and knows not why she is there. In saving her from the darkness, the two become fast friends. The non-human, wishing to help his very first friend recover her memories, makes for two beings he has heard about by way of rumors among the fae: the Thorn Mage Elias, and Chise.

A visual novel based on Kore Yamazaki's The Ancient Magus' Bride manga