Hair deformation treatment agent

A hair deformation treatment agent that contains components (A), (B), and (C). (A) Glyoxylic acid or a hydrate or salt thereof. (B) A compound represented by formula (1) [R 1 indicates H or a methyl group, A 1 , A 2 , and B indicate H, an alkyl group, an alkenyl group, or the like, D indicates H, OH, a methyl group, an alkoxy group, or the like, and E indicates H, a methyl group, an alkoxy group, or the like]. (C) Water.