It is commonly accepted that the theory mentioned in the following for chiral materials hold usually: chiral materials are optically active, and optical activity appears only when the material is chiral. However, is this always true? We discuss here whether (and how) this theory holds for molecules and nanomaterials. We describe macroscopic chiro-optical effects of ideal and pseudo two-dimensional materials, and nanoscopic version (local chiro-optical effects) of them, where we will find that the commonly accepted theory mentioned above sometimes breaks down. We also briefly discuss some unique chiral features of plasmonic materials relevant to the local chiro-optical effects.