I'm fairly certain that this also adds Accuracy, although I wont go as far to say im sure of the fact.

I used one yesterday while lvling Ninja in Bibiki bay, I was using sole sushi at the time and couldnt really notice a difference between the two.

This could mean 2 things
1. I didnt need to be using sushi
2. It adds Accuracy

for sure it definately must add somthing other than those other stats.