A block copolymer mixture containing a branched block copolymer characterized in that it has at least three types of polymer blocks with different molecular weights, each comprising a vinyl aromatic hydrocarbon as monomer units, the molecular weight distribution of a mixture of the polymer blocks S1, S2 and S3 each comprising a vinyl aromatic hydrocarbon as monomer units is within a specific range, and in a gel permeation chromatogram of the mixture of three types of the polymer blocks S1, S2 and S3, M1/M3 and M2/M3 are within specific ranges, where M1, M2 and M3 are peak top molecular weights of the respective polymer blocks.