Wash fresh ginger root and rub off skin. Julienne the ginger into 1/16" by 1/2" slices, place in bowl and salt them, stirring to coat each slice. Leave salted ginger in bowl for about an hour. Dry with paper towels and place ginger in a sterilized container/jar.
Mix rice vinegar and sugar in a pan and bring to a boil. Pour the hot mixture of vinegar and sugar over the ginger slices. Set aside to cool. The ginger will change color to a light pink. Cover the jar and store it in the refrigerator.
The red coloring of the beni shoga at noodle houses and Asian fast food places like Yoshinoya's is produced by using red perilla, also known as shiso. The shiso likely imparts some flavor to the ginger, however it's not vital, and the preserved ginger produced from this recipe is a fine substitute for the beni shoga available in Asian specialty stores and noodle houses.