A plug connector according to an embodiment includes: a connector main body which includes one pair of first sidewalls extended in a first direction and facing each other, and one pair of second sidewalls extended in a second direction perpendicular to the first direction, and facing each other; one pair of fitting nails which are coupled to the connector main body; and a plurality of plug terminals which are coupled to the one pair of second sidewalls, wherein each of the one pair of fitting nails includes: an upper surface which is in contact with an upper end of the first sidewall; a central reinforcement portion which is curved downward from the upper surface to come into contact with at least a portion of an outer surface of the first sidewall; and one pair of lateral reinforcement portions which are extended from both ends of the upper surface in the second direction to come into contact with an upper end of the second sidewall, wherein the central reinforcement portion includes a central solder portion which is extended downward from a lower end of the central reinforcement portion and encloses at least a portion of a lower surface of the first sidewall, wherein each of the one pair of lateral reinforcement portions includes: a first outer wall terminal which is extended downward; a second outer wall terminal which is spaced apart from the first outer wall terminal in the second direction and is extended downward; and a first inner wall terminal which is spaced inward from the second outer wall terminal and is extended downward, wherein each of the one pair of lateral reinforcement portions includes a lateral solder portion which is extended downward from at least one of the first and second outer wall terminals and encloses at least a portion of a lower surface of the second sidewall.