An ink set is provided including a first ink containing a polyvalent metal ion and a second ink containing a copolymer having a structural unit represented by the following general formula (1): wherein R1 represents hydrogen atom or a methyl group, and R2 represents one linking group or a combination of two or more linking groups selected from a group consisting of the following linking groups: —COO—, —OCO—, —O—, —NHCONH—, NR3CO— (R3 represents hydrogen atom or an alkyl group having 1 to 6 carbon atoms), an alkylene group having 1 to 12 carbon atoms, an alkyl ether group having 1 to 12 carbon atoms, and —NR4- (R4 represents hydrogen atom or an alkyl group having 1 to 6 carbon atoms).