Bartering Machine is one of Doraemon's gadgets that first appeared in the episode A Happy Mermaid Princess.
Appearance[]
Bartering Machine in its extended form.
It is a pink drum-like gadget with two robotic gloved hands that help in the barter. It has a slit which acts as its mouth, and the only thing it can say is "Give! Give!" in a robotic voice. When it urges the one disagreeing, it has a flexible pipe fitted to its bottom that can extend out and physically approach both the sides.
Functions[]
It is used to convince two people to make a barter decision even if either or both of them are unwilling to. The person against is forced to hand their export to the robot, while the other barterer hands their, to the other hand of the gadget. The robot then exchanges its hand position to give both their desired items.
In the episode, it was used by Doraemon to force the witch to give Mermaid Princess the potion which would give her anthropomorphic legs, in exchange of a headwear-starfish worn by the princess, even though the witch demanded for her melodious voice.