Japanese:

Chu-chu rocket
Nezumi o tasukerou!
Chu-chu rocket
Neko wa kowai!
Chu-chu rocket
Rocket wa su-go-i! TSUBABABAAAA

Translated to English:

Chu-chu rocket
Let's save the Mice!
Chu-chu rocket
The Cat is scary!
Chu-chu Rocket
The rocket is GREAT! WHEEEEEEEEEE