To avoid Nobita from getting scolded by his mother again, Doraemon uses a Room Guard Set to forbid Mom from coming into his room unless she says the correct password. Later on, Nobita decides to change the password to a harder one, but he cannot remember it. Which leads him to an electrical shock by the guard set!
Nobita's last word before getting shocked by the gadget which is, "Name Amida Butsu (南無阿弥陀仏)", which basically means when they think they're doomed.
This is where Doraemon's win got robbed by Nobita after showing his "gotcha" face near the end of the episode, including Nobita's mother siding her son telling Doraemon's gadget is way too dangerous.
