In a locked state of a structure, a connection part is positioned in a locking area, and a part of a locking protruding part overlaps with a part of a protection member base part in a lateral direction, when viewed from a top-and-bottom direction. Moreover, a third gap formed by a free end and an insertion edge part on a locking direction side of the insertion area in a longitudinal direction is shorter than a length of the locking protruding part in the longitudinal direction. When viewed from the top-and-bottom direction, a first gap exists between a connection outer peripheral face of the connection part and a locking edge part of the locking area in the longitudinal direction, and a second gap exists between the connection outer peripheral face of the connection part and the locking edge part of the locking area in the lateral direction.