A multiple coaxial connector system comprising: a plug; and a receptacle that is to be connected with the plug, wherein the plug includes a housing, a plurality of plug shells that are accommodated in the housing in a manner to protrude from the housing by a predetermined length A, a plurality of plug bodies that are accommodated in the plug shells respectively, and a plurality of plug contacts that are fixed to the plug bodies respectively, and the receptacle includes a receptacle shell that includes an accommodation portion configured to entirely accommodate ends of the plurality of plug shells, the plug shells protruding from the housing, in connector insertion and whose insertion-direction length B satisfies B < A, a plurality of through holes in which the plug shells are to be inserted respectively, and a guide hole that is positioned between the accommodation portion and the through holes and communicates the accommodation portion and the through holes to each other, and is formed in a manner to taper from the accommodation portion toward the through holes, a receptacle body that is accommodated in each of the through holes, and a receptacle contact that is fixed to the receptacle body and is to be fitted to the plug contacts. a plug; and a receptacle that is to be connected with the plug, wherein the plug includes a housing, a plurality of plug shells that are accommodated in the housing in a manner to protrude from the housing by a predetermined length A, a plurality of plug bodies that are accommodated in the plug shells respectively, and a plurality of plug contacts that are fixed to the plug bodies respectively, and a housing, a plurality of plug shells that are accommodated in the housing in a manner to protrude from the housing by a predetermined length A, a plurality of plug bodies that are accommodated in the plug shells respectively, and a plurality of plug contacts that are fixed to the plug bodies respectively, and the receptacle includes a receptacle shell that includes an accommodation portion configured to entirely accommodate ends of the plurality of plug shells, the plug shells protruding from the housing, in connector insertion and whose insertion-direction length B satisfies B < A, a plurality of through holes in which the plug shells are to be inserted respectively, and a guide hole that is positioned between the accommodation portion and the through holes and communicates the accommodation portion and the through holes to each other, and is formed in a manner to taper from the accommodation portion toward the through holes, a receptacle body that is accommodated in each of the through holes, and a receptacle contact that is fixed to the receptacle body and is to be fitted to the plug contacts. a receptacle shell that includes an accommodation portion configured to entirely accommodate ends of the plurality of plug shells, the plug shells protruding from the housing, in connector insertion and whose insertion-direction length B satisfies B < A, a plurality of through holes in which the plug shells are to be inserted respectively, and a guide hole that is positioned between the accommodation portion and the through holes and communicates the accommodation portion and the through holes to each other, and is formed in a manner to taper from the accommodation portion toward the through holes, an accommodation portion configured to entirely accommodate ends of the plurality of plug shells, the plug shells protruding from the housing, in connector insertion and whose insertion-direction length B satisfies B < A, a plurality of through holes in which the plug shells are to be inserted respectively, and a guide hole that is positioned between the accommodation portion and the through holes and communicates the accommodation portion and the through holes to each other, and is formed in a manner to taper from the accommodation portion toward the through holes, a receptacle body that is accommodated in each of the through holes, and a receptacle contact that is fixed to the receptacle body and is to be fitted to the plug contacts.