The hair follicle is an organ right. Your hair follicles were developed or developing a long time ago when you were a fetus just like other organs. This process consists of 2 cell types communicating with each other. These are mesenchymal type of cells and epithelial cells. It's like the birth of a hair follicle. A clump of 2 cells coming together to form a hair follicle. That is exactly what Dr. Tsuji is trying to replicate. He will extract these type of cells from your hair follicles and multiple them. Then he will add them together to mimic that process that happened when your hair follicles were developed. Only the begin period, because as soon as the beginning of the process is observed he will deliver them into the scalp. This is called a "primordium";
Then in the scalp this would develop into a fully functional hair follicle. So the thing that would delivered is the very beginning of a hair follicle.
You see on that picture in that movie where your cells would get added together in a 3D environment and then they would develop into the beginning of a hair follicle and then delivered into your scalp.
Now what's so exciting about this too is that a healthy hair follicle at least like in your donor hair displays high plasticity and regeneration potential. After all it cycles constantly between anagen-telogen-catagen and this relies heavily on mesenchymal-epithelial interaction too. In that aspect it's unique as an organ.
Also, when you CUT a hair follicle in half below the bulge (epithelial cells) and above the DP (mesenchymal cells). The hair follicle has capacity to regenerate itself. This has already been proven. Often in hair transplant surgery for example hair follicles get transected but regenerate.
This is absolutely awesome f*cking great in my opinion.