Generalities always fail on the exceptions, but I think most Japanese share most of these characteristics:

1. Honest (in the law-abiding sense).

2. Dishonest (in the sense of not always giving you the truth, even about important matters).

3. Hard-working.

4. Diligent. (Precise attention to detail).

5. Peaceful.

6. Group dependent (conformist).

7. Gracious (especially the women).

8. Polite (once they've formed any sort of social link with you).

9. Rude (with anonymous strangers).

10. Inefficient. At times you can see quite a few Japanese working very hard, and accomplishing relatively little.