Putting aside the cost and trouble with finding a one way car rental, I'm still trying to figure out how someone thinks they can travel the length of the country in 7-14 days and stop in most of the cities?! I could spend a week just wandering about a single prefecture and still know full well I hadn't really seen much of it.

Mind you, stopping to get out and take a photo then instantly leave and say you've "been to X, Y, Z & here's the photo" would be very Japanese.