The Working Mouth and Eye

Suneo has recently encountered some strange things. He sees eyes and mouths flying into his house, making his comic books sticky and sweet. Everyone suspects Doraemon used a gadget to do it, but Nobita says it's Suneo getting his comeuppance. While doing his homework, Nobita tricks Doraemon into going out by saying there's a dorayaki party outside, but there's nothing there. When Doraemon returns and sees Nobita doing his homework, he thinks something's wrong and uses a gadget to check Nobita's temperature and pulse, even going so far as to draw his blood, which Nobita beats up. When Doraemon checks Nobita's homework, he finds it all correct. After finishing his homework, Nobita receives a call from Shizuka, inviting him to her house for cake. After the call, Nobita uses the excuse of a dorayaki party to send Doraemon away again, secretly taking back the gadget. On his way to Shizuka's house for cake, Nobita is dragged off to watch the shop by Gian and his friends who are going to play baseball. At Shizuka's house, Dekisugi recounts how a strange mouth rummaged through his homework. Doraemon, overhearing Dekisugi's description, guesses Nobita is behind it and tells Shizuka and Dekisugi. While Nobita fantasizes about Doraemon eating cake, Shizuka advises him not to eat it all and to save some for Nobita. Meanwhile, Nobita, who is minding the shop, pulls out the "Working Mouth and Eye". It turns out he took the gadget from the Future Department Store while Doraemon was away and used them to rummage through Suneo's comic books and Dekisugi's homework. He uses the mouth and eyes to go to Shizuka's house and eat the cake clean. Doraemon, Shizuka, and Dekisugi all recognize Nobita's voice. After finishing the cake, Nobita uses the mouth and eyes to play pranks on Gian in an empty lot, but is caught by Suneo. After Doraemon returns home, he finds the delivery slip from the Future Department Store and questions Nobita about it, but Nobita pretends not to know. Suneo and Gian put the gadget in a glass jar and add pepper, mustard, chili, lemon, onion and pickled plum. When Nobita tries to distract Doraemon, he is in great pain from the multiple attacks of pepper, mustard, onion, and pickled plum, and cries out to Doraemon for help. However, Doraemon has already guessed that Nobita is behind it and deliberately pretends not to know anything.