A system for coupling at least one flexible hose is provided that includes first and second annular connecting elements. In a system mounting position, the second element is inserted partially into the flexible hose and the first element is mounted on the second element to compress the flexible hose. The first element includes a tubular body, and a proximal end having an annular part. The tubular body is divided from the annular part by axially extending openings that form at least two hooking portions with hook-shaped ends. The second element includes a first sealing projection and a second retaining projection formed beyond the first sealing projection. The second projection cooperates with the hooking portions. More specifically, the annular part comprises an annular inner protrusion to form a constriction between a bottom and top of the sealing projection side facing the said first end of the second element.