It starts with a baseball thrown into a window. The owner scolded Nobita even though Gian does it, he forces Nobita to admit he did it. He scolded to Doraemon, "why doesn't the owner change the glass to metal?". Doraemon gives Nobita the Materials Quality Changing Machine and he changes many things to another material. Gian took it but requested Doraemon to repair it after accidentally turning his house to a paper house.
