It helps if you have it the right way up....
It's the combination Nissan/Prince emblem, introduced after the 1966 merger. It's a monogram with stylised letter 'N' and letter 'P' combined to form a cypher. It was derived from the old single letter 'P' Prince logo, and intended to pay respect to the history of the Prince marque when it came under the wing of the Nissan group.
Here it is on the front of the Nissan R382 sports racer. This is the correct orientation: