I played as a 24/15 archer/melee. Not with a nodachi and yumi, but similar. I used longbow and a 1h weapon. With 8 Power Draw and 8 Power strike, you can take down people with only a few arrows. When someone closes in, they will not expect your devastating swings at all. The only problem is that you can't wear the heavy samurai armor - there just won't be enough WPF for your archery to meet the needed minimum.
With the light strange armor set you could probably pull this off - the higher strength will give you a few extra hit points to make up for some of the lost armor.