A connector set includes at least one of a header and a socket and a jointer. The jointer extends in a direction and is configured to couple the header and the socket so as to be in parallel with each other. The jointer includes first jointer connecting portions provided at both end portions thereof and extending in a second direction perpendicular to the first direction, and which are configured to engage first connecting portions provided at both end portions of the header, and second jointer connecting portions provided at both end portions of the jointer body and extending in a third direction opposite to the second direction, and which are configured to engage the second connecting portions provided at both end portions of the socket.