We know that Matsumura, inventor of linear karate, set out to fight every sifu in Okinawa, and humiliated them so badly that no one would agree to fight with him. This is how he got his position as the Minister of Military Affairs in the Shuri government.
So we know he created hard-style karate, and we know he beat up a lot of soft stylists, but how do those two ideas connect?
In 1975, Mas Oyama filmed a very self-serving movie about a kyokushinkai full-contact tournament in Japan, intended as a marketing project for his world-wide kyokushinkai karate organization. Oyama had been a student of Funakoshi at one point, and then went yamabushi and invented his own kind of karate. The film is called Fighting Black Kings, for no apparent reason. You can view it in ten segments on YouTube.
In segment four of Fighting Black Kings, around 6:57 into the segment, there is a full-contact match between a kyokushinkai fighter and a Chinese stylist from Hong Kong. There is a similar match at the beginning of segment five.
It's a massacre. The Chinese fighters absolutely rained punches on the Japanese fighters, and the punches just bounced off. In the second match, the karate fighter just stood there in apparent astonishment while his opponent chain-punched him in the chest. Then, losing patience, the karateka threw a single reverse-punch and the fight was over. The Chinese guy had to be helped out of the ring.
At first I thought I might be seeing a replay of Matsumura's victory over the Chinese fighters of Okinawa, but on reflection I realized that the tournament rules were playing against the Chinese fighters. Kyokushinkai rules prohibited punches to the face. I didn't see any bloody noses in this lengthy and brutal tournament. If a chain-puncher can't hit you in the face, he's fatally handicapped. The rapid-fire, uncommitted punches have little effect when directed at the opponent's chest. They need to be hitting mouth, nose and eyes in order to produce the effect they expect.
Add to that the fact that the kyokushin guys tend to be big, and have taken literally thousands of blows to the torso in their training. The Chinese fighters were kind of skinny.
Fighting Black Kings is full of karate demos, meaning every kind of breaking stunt. For instance, here is the stunt where the fighter does a flying side kick entirely over a speeding car, lengthwise. Better get the timing right on that one, buckaroos.