A reduction in the durability of a coupling member coupled to a buckle is suppressed. A lift-up buckle device includes a buckle that engages with a tongue inserted through webbing worn by an occupant, and wires that each have a portion fixed to the buckle and that are displaced to move the buckle. The lift-up buckle device also includes a wire guide that includes a guide groove that guides the wires, and a soft lower cover that engages with the wire guide and covers the wires. A dimension of an end portion on the buckle side of the guide groove is set so as to increase on progression toward the buckle side.