The present disclosure includes: an optical fiber ribbon including a plurality of optical fibers having an outer diameter of 0.2 mm or less and a ribbon resin that integrates the plurality of optical fibers in a parallel state; and a coating resin that covers the optical fiber ribbon. The optical fiber ribbon is in an assembled form in which the plurality of optical fibers are assembled so that a length in an arrangement direction is shorter than that of a case where the optical fibers are arranged in a row, and the optical fiber ribbon is covered with the coating resin in the assembled form.