actually sir you are confusing your grading systems.
there is the japanese quality grade which is 1-5 (5 being the highest)
and there is the BMS grade (beef marbling standard) which is 1-12 (12 being the highest which does not leave japan).
anything BMS 8 or higher is grade 5 kobe beef. BMS 11-12 is literally the best kobe you can get.