Hinge

A hinge, comprising:

• a vehicle body-side hinge member that includes a vehicle body attachment portion for attachment to a vehicle body;
• a back door-side hinge member that includes a door attachment portion for attachment to a back door and a coupling portion extending from the door attachment portion toward the vehicle body-side hinge member, the back door-side hinge member including a reinforcing rib which is continuous along an entire periphery of an edge portion of the door attachment portion such that the reinforcing rib extends from a first edge, in a width direction intersecting an extension direction of the coupling portion, to a second edge, in the width direction intersecting the extension direction of the coupling portion;
• and
• a rotational support member that couples an end portion, at a side of the vehicle body-side hinge member, of the coupling portion together with the vehicle body-side hinge member, and that supports the vehicle body-side hinge member and the back door-side hinge member so as to allow relative rotation of the vehicle body-side hinge member and the back door-side hinge member.