Dogen Zenji's Zazenshin consists of the "Non-Thinking" of Grand Master Yakuzan Kodo, the dialogue between Zen Master Nangaku and and his disciple Zen Master Baso Doitsu beginning with "Planning to become Buddha", "Polishing to make Mirror," and then Zen Master Wanshi's Zazenshin and Dogen Zenji's own Zazen shin.

Using the character for "shin" in acupuncture, he shows the essence of zazen. He indicates the way of Zazen called non-thinking, not comprehending but as actual practice. The text is difficult to understand without the guidance of a clear-eyed master.
I had been studying Dogen Zenji's "Shobogenzo" by myself. In 2016, I listened to the talks of “Shoubogenzo” by Kando Roshi and found it was very easy to understand. Since then, I have learned from Kando Rhoshi, and with his permission, I have transcribed and published his teachings. I feel that with his explanation, I can understand Dogen's original text and get his true meaning across.
The reason why I attempted to translate it into English is that I thought I could express in English the true meaning of Dogen Zenji that I have come to understand through the practice of zazen and publishing under the guidance of Kando Roshi. The annotations are taken from Kando Roshi's advocacy.
I am not sure if I have expressed the pivot of Zazenshin as shown by Dogen, the way of practicing Zazen in a way that is not affected by the way of human thinking, and the state of the masters beyond thinking, yet I would appreciate your comments and suggestions.
 In the end, I would like to introduce a passage from Master Kando's speech.
"As Dogen Zenji said, the Zazenshin of Zen Master Wanshi may seem to be a methodology on how to do zazen, but it is already beyond methodology.
Each one of us is in his or her own state right now, so there is no indication that we are going to get there. Everyone is showing us the truth of themselves as they are sitting right now, right away. I think that's something I'm very grateful for. If I may add a little more, we are now able to live a proper life before we understand or know. Furthermore, it was quite a while later that we started thinking about things like the other side and this side. In the beginning, there was no need to think about the other side and this side, and suddenly we are here in the truth of ourselves. It's the same for everyone. If you look at the way you are sitting now, you can see that there is no sign of anyone else anywhere. And we are here without even saying that it's just our appearance. This kind of thing must be at the core of Zen master Wahshi's Zazenshin.”
Sep. 2021,
Taihaku Sokan. S. Tatsuta
 

Brief History of Venerable Kando Inoue Roshi.
Born in Hamamatsu City, Shizuoka Prefecture in 1944. Fifth son of Gien and Yoshie Inoue.

Associate master of the Soto Zen School, and the Todo of Shorinji Temple.
The 24th restoration founding of Shorinji Temple.
He was ordained in 1953. After working as a monk at Hoshinji Temple, and at Daihonzan Soji-ji Temple, for many years, he served asYakuryo; the head of the Kaphaisai in Fukuroi City.
In his teens, he became aware of and continued his studies and later received Dharma Seal transmission; a certificate of approval from his father and teacher, Gien Inoue Roshi. He has been teaching zazen in Tokyo, Shizuoka, Kansai, Okayama, and many other places.
References

Ebook “Shobogenzo Zazenshin" by Inoue Kandō Rōshi 

Youtube recording “Shobogenzo Zazenshin” by Inoue Kando Roshi

The First Session https://youtu.be/yE_juUBbicU

The Second https://youtu.be/ccUPphIw7xw

The Third https://youtu.be/z1_oUFI5LLQ

The Fourth https://youtu.be/jSujrHg6d9s

The Fifth https://youtu.be/NsxAu2qTjyk

The 6th https://youtu.be/NlX1xMISRoE

The 7th https://youtu.be/9KKyyhIKkTc

The 8th https://youtu.be/nF1KMsU4Mqg

The 9th https://youtu.be/fnFEjg-B1OI