To make a multi-joint curve mechanism smaller and lower in cost and utilizes it for pseudo-feeling expression and emotion expression.

The multi-joint curve mechanism is constituted by connecting links which are rotatably supported one another by making two or more gears including the gear at an input side and the gear at an output side to gear with mutually. Each link is constituted so as to be rotatably supported by making odd number of gears to gear with mutually, and the gear at an output end rotates in the same rotational direction as the rotational direction impressed to the gear of an input end. Between adjacent links, the gear at the input side of one link and the gear at the output side of another link is shared, and the shared rotational axis of the gears constitutes the joint's degree of freedom of the multi-joint curve mechanism.