I'm sure opinions on this subject conflict. Kajukenbo guys will beat on eachother before competition to get the blood flowing, but they don't exactly plan to walk into punches on the street. I assume they kyokushin guys are more defensive fighters in that they counter attacks rather than relying on being first.
Sean
Actually, kyokushin tend to be very aggressive.
In defense there is a lot of angling the body to cause glancing blows with reduced impact, and lightly tapping attack off aim to "less sensitive targets". Defensive footwork tend to be primarily used at longer and middle ranges. Once in close it tends to get down to pure slugging it out with rapid power punch combinations and knees to see who folds first. Kyokushin require a lot of conditioning to blows.
Kyokushin guys seldom moves straight backwards. If the step back they do it at an angle.
Some offshots like Ashihara and enshin preaches more circular footwork even for closer ranges, but in competition there is little difference. They also allows more grabbing and throwing, which is not allowed in kyokushin competitions -which makes circular movement at close ranges easier and more effective.
Offensively, you aim for week points (solar plexus, floating ribs, the liver and so on). You lowkick the opponents legs to slow him down (and maybe even lowkick KO him) and his shoulders/biceps to slow down his arms, and slowly draw his guard down to cover his body by inflicting pain to chest and ribs, then knock him out with a quick highkick or knee once he no longer guards his head effectively.
It is basically a pure competition tactic adapted to the rules, and not a good idea in selfdefense, when slowly wearing the opponent down is not smart