A sliding mechanism includes first and second members slidable relative to each other and a grease composition interposed between the first and second members and containing a thickening agent and a base oil, wherein the grease composition contains lithium 12-hydroxystearate as the thickening agent and dioctyl sebacate and/or poly-α-olefin as the base oil; and wherein at least one of the first and second member has a sliding surface coated with a hard carbon film of diamond-like carbon.