Multi-Purpose Cleaner is an episode of the 1979 anime.
Plot[]
On the way to school, Nobita and Suneo meet Gian, who had previously been down with the flu and taken medical leave. Gian wants to view Suneo's notebooks to catch up with the school work, so the latter helps him out. Later, Suneo reveals to Nobita that he shouldn't have let Gian view the notebooks - because he used a pen to scribble drawings on it saying bad things about Gian, and they can't be erased - so he seeks Doraemon and Nobita's help.
After much deliberation, they decide to help in exchange to borrow a manga and an autograph from him. Doraemon takes out the Multi-Purpose Cleaner to erase the drawings. However, after Gian defends Suneo from Haruo claiming that he used a remote-controllled airplane to smash one of his windows in his house, Suneo decides to give not only the notebooks, but also the manga and autograph to Gian, to Doraemon and Nobita's dismay.
Therefore, they decide to pay Suneo back by using the cleaner to restore Suneo's drawings on the notebooks and transferring the contents of the manga and autograph to blank pieces of paper at their house. Seeing that the manga and autograph are empty and Suneo's drawings on the notebook, an enraged Gian chases after Suneo, with Doraemon and Nobita ignoring them.