You'll become his shadow. No one can know you are helping him. Especially Haru.
8 seconds sound clip from the Beverly Hills Ninja movie soundboard.
You can hear this line at 00:19:58 in the Blu-ray version of the movie.
Quote context
[...]
- Thank you, Sensei. There is no better father that a boy could have had.
- Wait! Wait! Wait up! Goodbye, everyone!
- I'm surprised, but I'm going to miss him.
- No, you will not, because you are going with him.
- No, please! Anything but that!
- Goodbye, my family! See you, and don't worry.
- You'll become his shadow. No one can know you are helping him. Especially Haru.
- I am sure you would like to know who I am and what I do, but as part of my creed I cannot tell you.
- You see, my identity must remain mysterious and my mission secret. I cannot reveal it to you.
- Why not?
- Because I would then have to kill you.
- Daddy! Daddy, he said he was gonna kill me!
[...]