To avoid Nobita getting scolded by his mother again, Doraemon uses a room guard set invention to make Nobita's mother not come into his room unless she says the correct password. Later on, Nobita decides to change the password to a harder one, but he can't remember it, which leads him to an electrical shock by the guard set. Remade as Entry to Nobita's Room is Forbidden in the 2005 series.
