An object of the present invention is to provide a composition having flexibility. A composition comprising a graft copolymer in which a monomer, including a (meth) acrylonitrile and a (meth) acrylic acid ester as a main monomer, graft-copolymerizes to a backbone polymer having a polyvinyl alcohol, wherein the polyvinyl alcohol has a saponification degree of 50 to 100 mol %, a content of the composition of the polyvinyl alcohol is 5 to 50% by mass, a total content of the (meth) acrylonitrile monomer unit and the (meth) acrylic acid ester monomer unit is 50 to 95% by mass, a content of the (meth) acrylonitrile monomer unit in a total of 100% by mass of the (meth) acrylonitrile monomer unit and the (meth)acrylate monomer unit is 20 to 95% by mass, a content of the (meth)acrylate monomer unit in a total of 100% by mass of the (meth) acrylonitrile monomer unit and the (meth)acrylate monomer unit is 5 to 80% by mass, the (meth) acrylic acid ester is a monomer whose homopolymer has a glass transition temperature of 150 to 300 K.