In cell system, dynamic behaviors of nanometer- and micrometer-sized living tissues are induced through various chemical reaction networks accompanied with molecular conversions of key molecules. However, such hierarchy between macroscopic dynamics of cells and molecular conversions is very complicated. Here, as a tool for understanding the essence of the dynamic behavior found in cell system, two chemical systems for droplets exhibiting cell-mimicry behaviors have been described: transformation of molecular aggregates and locomotion mode of oil droplets.