Controlling the morphology of the molecular assemblies formed by surfactants via photoirradiation enables the controlled release of incorporated substances, which can be applied to delivery systems for drugs and active ingredients. Micelles formed by azobenzene-based cationic surfactants exhibited changes in the solubilization capability of model perfumes upon photoirradiation. This controlled release was derived from changes in micelle formation by photoirradiation using small-angle neutron scattering (SANS) analysis. Conventional photo-responsive surfactants and molecular assemblies have slow response rates, making it difficult to control their functions at desired times. The recombination reaction was accelerated using the confined inner space of the micelles formed by the surfactants. In situ SANS measurements revealed rapid morphological changes in the micelles formed by amphiphilic lophine dimers upon ultraviolet (UV) light irradiation. Moreover, rapid controlled release of a model drug was achieved by UV light irradiation using photo-responsive micelles. By focusing on the dynamics of photo-responsive systems, the rapid system can be realized for the controlled release of drugs at the desired time, thereby developing an efficient and precise delivery system for active ingredients (such as drugs, fragrances, and nutrients)Self-assembly.Stimuli-responsiveness