Abstract: A plug-in heater for hot curlers is constituted in the following manner: because the power plug can be positioned at the storage location, it is constituted to possess a compact size; in particular, because the power plug can be positioned at the protruding positions in two perpendicular directions (a rear-side protruding direction and a lower-side protruding direction), the range for inserting the power plug can be expanded even when the electrical outlet is located at different locations at the housing facilities.

Abstract: The invention concerns a hair treatment method using a hair treatment liquid having been electrolytically treated by passing current through hair. The hair treatment method features applying a hair treatment liquid to hair and electrolytically treating the applied hair treatment liquid by passing current through the hair. The invention also concerns a hair treatment tool which is substantially made of an insulating material and features that an anode electrode bar and a cathode electrode bar both connected to a power supply are disposed such as to be in contact with hair, the hair having been imparted with conductivity being pinched between the two electrode bars to pass current through the pinched hair.