Ring-opening polymerization (ROP) of cyclic peptide monomer of γ-propargyl-L-glutamate N-carboxyanhydride (PLG-NCA) was originally initiated by non-emissive, ring-close rhodamine 6G hydrazide (R-C). However, instantaneously after adding PLG-NCA to R-C, the spirolactam ring of R-C was opened by PLG-NCA, rendering emissive, ring-open R-O to initiate ROP of PLG-NCA. The emissive R-O moiety therefore produced fluorescent R-PLG with aggregation-induced emission (AIE) properties. Moreover, R-PLG was found to exhibit photochromic properties with good fatigue resistance and long lifetime when forming metal complexes with Sn(II) and Fe(III). In the dark, irradiated metal complexes slowly (~50 min) restored to the initial state. This research provides foundation for the development of new photochromic materials with long lifetime.