Younger brother of Shun. He is from Canaan, a town in Agartha.
His encounter with Asuna occurred while he was attempting to retrieve an ancient stone called the "Clavis" that his brother had left in the underworld. Unbeknownst to him, Asuna followed him to Agartha along with her teacher. This prompted the village elder in Canaan to order Shin to kill her. However, instead of killing her, Shin guided and protected Asuna throughout her journey, all with the same goal of finding the truth about his brother, Shun.