Kyokushin karate is considered the hardest and most physical karate.
There is very great emphasis on a high standard of physical fitness, and a strong competitive culture where you must prove your ability as a karateka in fighting. Kyokushin kumite differs from a lot of other karate styles in that it is bare knuckle fighting, full contact, with no head or groin strikes allowed, and no attacking someone’s back.
It is supposed to be a test of strength, endurance and spirit.
During the competition in Kyokushin Karate it is forbidden to beat by the hands to the head because of the risk, which represent full-contact hitting. On high-speed punches it is harder to react than when kicking.
Kyokushin on the other hand is a lot more brutal than other traditional karate styles. Rather than seeing who hits first, it’s all about who gets to withstand first and get the most points in the process.
Fights are continuous and hard contact is a thing. You can even do knock outs. So, you are allowed to hit anywhere on the body except the groin and you cannot punch to the face BUT you can kick the face.
Mas Oyama often repeated, “Kyokushin karate is not dance karate! It’s not kenka (brawling) Karate! It’s BUDO Karate!”