The present invention relates to an organopolysiloxane graft polymer including an organopolysiloxane segment as a main chain thereof and an unsaturated monomer-derived polymer segment as a side chain thereof, in which a content of the organopolysiloxane segment in the organopolysiloxane graft polymer is not less than 35% by mass and not more than 70% by mass, and the unsaturated monomer-derived polymer segment contains a repeating unit derived from a nonionic unsaturated monomer having a glass transition temperature Tg of 60° C. or higher (except for a repeating unit derived from an unsaturated monomer containing an amino group) in an amount of not less than 40% by mass and not more than 90% by mass, and further contains a repeating unit derived from a cationic unsaturated monomer in an amount of not less than 10% by mass and not more than 60% by mass.