A resin composition for an aqueous paint containing different phase structure emulsion particles obtained by multi-stage emulsion polymerization as a binder, wherein the different phase structure emulsion particles have an outermost phase formed by an emulsion polymer of an ethylenic unsaturated monomer, having a glass transition temperature of from −50° C. to 10° C., and satisfy the following conditions (1) to (3): (1) the emulsion polymer forming the outermost phase contains from 1 to 20 mass % of an ethylenic unsaturated monomer having at least one of a polyethylene glycol chain and a polypropylene glycol chain, (2) at least one phase of inner phases from the outermost phase of the different phase structure emulsion particles comprises an emulsion polymer of an ethylenic unsaturated monomer having a glass transition temperature of from 30° C. to 110° C., and (3) the binder has a minimum film-forming temperature of at most 10° C.