Watch Bombuj. While Doraemon is asleep, a famous thief comes and steals his cat-bell. Without his cat-bell, Doraemon starts to act more and more like a normal cat. In order to stop this, Nobita, Shizuka, Suneo, and Gian have to go and search for his bell, so they go to a factory where all of Doraemon's gadgets are made.