Tai Sai Festival was a wonderful day. We got there a little bit early to help with the final preparations and saw the Doshu as we walked up the path to the Shibu Dojo. The event itself was a ceramony conducted by Shinto priests, where they took turns to chant different sutras and make offerings to the various shinto deities. And assist the others present on stage to make their offerings. The Doshu his wife and son and other various high ranking Aikido instructors.
Nemoto sensei (and a couple of friends) with his Uchideshi group:

Shinto priests approching the Jinja and making offerings:


The ceramony itself took about an hour (I think), I have the paper with the chants in Hirigana and Kanji which will sets me up with reading homework for the next decade. After the main ceremony the Doshu performed a ~5 minute demonstration, I was quite close to the front (about three people) so I got quite a good view.