My name is....

• My name is... (grammatically correct)

  Ms. Hayashi: What is your name?

  Mr. Smith: My name is Smith.

  Ms. Hayashi: (O)namae wa nan desu ka.

  Mr. Smith: Watashi no name wa Sumisu desu.
• My name is... (the natural correct)

  Ms. Hayashi: What is your name?

  Mr. Smith: I am Smith (My name is Smith).

  Ms. Hayashi: (O)namae wa nan desu ka.

  Mr. Smith: Sumisu to moushimasu.