The female protagonist of the story. She has red hair and jade-green eyes. She is the former princess of the fallen kingdom of Mactarode which once existed in the northern region of the continent. Arwin tackles the dungeon in search of a treasure she can use to rebuild her fallen kingdom, which was destroyed by monsters. She has a childish side that she only shows to Matthew. She is the leader of the adventuring party Aegis, one of the foremoest parties in the city of Gray Neighbor, also called a dungeon city.