KS90 A hair treatment method comprising steps (i) to (iii): step (i): a step of applying a hair treatment agent containing components (A) and (B) to hair； step (ii): a step of leaving the hair to stand, after step (i)； and step (iii): a step of applying a hair treatment agent containing component (C) to the hair, after step (ii), (A) a compound selected from the group consisting of a glycylglycine derivative, a polyglycerin, and an alkyl glyceryl ether； (B) a carboxylic acid having an inorganic value of 250 to 450 and an organic value of 50 to 250, or a salt of the carboxylic acid； (C) an aromatic sulfonic acid having a molecular weight of 300 or less, or a salt thereof.
