Tenchi is not only to be found in tenchi nage.
Every Aikido technique is tenchi.
Before descending to earth, one must ascend to sky, always and in all techniques.
Only in this way does the virtue of Aiki allow man to become a link between heaven and earth. 合氣ハ練習ノ德ニ依リテ自然ニ會得ジ得ルモノナリ : Aiki is found in this practice. Tenchi is the top and the bottom, the sky and the earth, the universe, the kingdom.
This is the information given by O Sensei in his book Budō, in particular through this photo on page 21 of the original edition, which cannot be understood unless one understands tenchi as a principle of action:
And it is this fundamental principle that the video also talks about:
