Just in case the poster of the request can only read English:
The Japanese I wrote was corrected by PolarBear, who made it into much more beautiful, poetic Japanese (Thanks, PolarBear!
)
He also kindly corrected the Romanized Japanese, but the literal translation should now read:
May the Japanese language be the entrance gate to your wealthy life. Make this ninja a guide towards your (achieving) honor.
BTW, the verb "make" in the second sentence is in a poetic, classical command form, as if it were from one Edo-period ninja to another -- beautiful, PolarBear!
Just for others who appreciate the beauty of language too!