Your name is your identity (Respect your name) (僕の名前は三葉ケン一の巻) is episode 372 of the Ninja Hattori-kun 1981 anime.Kenichi starts to dislike his name, leading to Hattori using his Ninja techniques to make Kenichi respect his name.
One day, Kenichi arrives from school in a rather down-in-the-dumps mood. When Mrs Mitsuba asks about the long face, Kenichi asks how he got his name, to which Mrs Mitsuba replies that his name was chosen by his grandad. Kenichi promptly goes up to his room, and meets Hattori, who asks what's been happening. Kenichi tells him that when he was in school, Kemumaki said that Yumeko's name brought hope to others, while telling Kenichi that his name means that he is a psychopath. However, Hattori refuses to help him, saying that he must be grateful for his name, and if he doesn't like it, he might as well change it.
At dinner, when Mrs Mitsuba addresses Kenichi by his given name, Kenichi grumpily replies that he doesn't go by that name anymore - Hattori can have it. Hattori, Shinzo and Shishimaru think of a plan, and Shinzo comes up with the final idea.
Next morning, Mrs Mitsuba is by Kenichi's bedside, telling someone numbered "47695" to wake up. Kenichi is puzzled. Just then, Hattori jumps down from the ceiling. When Kenichi calls him by his casual name, Hattori replies that he goes by the number 1007. Distressed, Kenichi leaves the house, still dressed in his pyjamas. He is shocked to see that the nameplate has changed to a number. He goes around, and sees that all the letters on the nameplates have been replaced with numbers. While in town, he bumps into Yumeko, who says that she is now known as 66987. Shocked, Kenichi runs off, and Yumeko reveals herself to be Hattori.
At home, when Mr and Mrs Mitsuba bicker about numbers, Kenichi cracks and says that he's had enough. Hattori, having reached the final stage of his plan, freezes Kenichi and takes him upstairs.
The next morning, Kenichi wakes up, and, thinking that he's had a bad dream, tearfully tells Mrs Mitsuba that he's Kenichi. Hattori is pleased that his plan has worked.