Nobita Becomes Shizuka-chan (しずかちゃんになったのび太 Shizuka-chan ni natta Nobita) is an episode from 2005 anime series.
Shizuka invites both Dekisugi and Nobita to taste her baked cookies, which both of them agreed. Nobita comes home, and remembers he forgot to pull weeds as he promised for Mama, but he may be late for Shizuka's cookies. Nobita secretly goes upstairs to leave his bag and is surprised to find Mama showing up from Doraemon's closet. She forces him to study and do homework. Giggling, she laughs very hard, and she is revealed to be Doraemon in disguise.
Nobita borrows Doraemon's gadget, the Free-Size Toy Camera to be Shizuka and, while she is doing homework in her room, "Shizuka" turns up, informing Dekisugi that the cookie-tasting has been cancelled. Doraemon uses the gadget again to be Nobita for him to replace Nobita in pulling the weeds while the real Nobita tastes Shizuka's cookies. Suneo overhears that Nobita is going to Shizuka's house to taste cookies as Nobita shouts it in the sky.
Realizing that he was fooled, Doraemon throws the Nobita costume in the streets. Suneo spots it and wears it to fool everybody, especially Gian. Nobita sees Shizuka waiting very patiently for Dekisugi while he himself can't wait to taste, and goes to Dekisugi's house telling him about the cookies. Nobita while flying was spotted by Mama and drags him to the house while "Nobita" substitutes him to go with Dekisugi to taste the cookies.
After pulling the weeds, Mama congratulates him and she is revealed to be Doraemon yet again. Infuriated, Nobita chases Doraemon in the streets. He later remembers about the cookies and goes back to Shizuka's house.
Along the way, several classmates of Nobita turn up out of the blue and beat Nobita up, but that does not stop him from going for Shizuka's cookies. Gian, who is hit by "Nobita" with a football earlier, punches him for insulting him. A beaten Nobita sees Shizuka sending Dekisugi and "Nobita" out and realized he has been replaced.