Cane said his injury happened with about 10 minutes left in the game and at a New Zealand lineout.
"Caleb Clarke carried. I went in to clean from the outside, and David Havili came from the inside. I was the cleaner, the Japanese player moved late, and we hit heads.
"I got up slowly, and without having done my cheekbone before, I knew I had probably done my cheekbone. I could feel it when I put my hand on my head. And I could feel the blood in my mouth.
"It was sort of sore but numb at the same time. Because it wasn't too sore, and there were only 10 minutes to go, I wasn't too concerned, but I knew it wasn't too good.
"The game was in the balance at that point, and it didn't restrict my ability to play and perform so I was happy to carry on."
After the game, the team doctor pressed on his cheekbone, and it wasn't sore, which gave them hope it wasn't fractured.
But a CT scan at a hospital revealed two breaks - one below his left eye and one to the left of his left eye, which was where he felt it at the time of the collision.
Cane said he was gutted firstly at the emotions when it appeared not to be broken but, then, realising he was out of the tour because he had been looking forward to the remaining Test matches and, hopefully, having the team finish the year strong.
Coping with injuries was always frustrating, and they were the lows surrounding the game.
"Knowing the work that goes into getting on the field, you want to be out there with your teammates doing what you can to perform well, and play well, in the black jersey."
Cane was pleased with how the side came through to achieve the win. Down to 14 men, there was plenty riding on it. But the players showed good composure, belief, and character to work hard and defend the way they did.
"Although it wasn't a vintage performance, there were some areas we were proud of, but there were other areas we weren't so sharp at.
"It just goes to show how far Japan have come, and it was a good experience for a lot of guys who have been helping the starters prepare for a long period this year. They got their opportunity and [to experience] the pressure of Test match rugby."
The All Blacks were not surprised by the intensity of Japan's defence. They had studied their play, and Japan had been in camp for six weeks preparing for the All Blacks while also playing three games against Australia A.
"We were hoping with our attack that we would be able to negate that a little bit and after a few quick phases we would find our way through, and we did at times, but they also got the better of us at times defensively. So it was a tough Test match."