Awesome post, Maichan. I'll just add my photos and thoughts to the post you started. Thanks for letting me tag along.
Recap of the night:
I left Santa Barbara around 2pm. I got to Maichan’s place around 5:30ish, I think? He introduced me to his cute dog, Momo (you might remember Momo has randomly picked out a winner in the Usagi trivia contests here). Maichan drove to Temecula and we got to the exhibit around 7:30ish. Grusagi and his friend had been there since the openning at 6:30pm and waited for us.

Outside of the museum there are two nice banners (collector items

)
In the front, the museum store is on the right. Julie and Emi were working the store helping customers out as we walked in. We waved but didn’t want to interupt so we moved to the exhibit. The exhibit was upstairs but I have no sense of direction, so I walked in a circle until we saw the elevator. Grusagi walked out but I wasn’t paying attention, so Maichan (who hadn’t met Grusagi yet) walk passed him and went upstairs.

The first thing out of the elevator is an ungraded Albedo #2 from Stan’s personal collection.
Maichan and I saw Stan talking to a crowd of people. We didn’t want to interupt so we headed the the food (Turkey sandwhiches, hummus, chocolate chip cookie - great food for after a long drive).

They had a classical guitarist playing. He was playing this instrumental song I remember from the movie La Bamba that is sweet. It made me very happy and I told him he was awesome before he left.

If you follow the wall on the left of the photo above, they have a projector showing the latest TMNT / Usagi tv show crossover on the wall. Next to it is an original cell from an early TMNT TV show.

There is a lot of original art. And they have a wall focused on TMNT crossovers.

Original art for the TMNT/Usagi 2018 Mondo Poster

Sakai varient Usagi/TMNT crossover

Lots of awesome orginal colored covers

Stan drew Usagi and Kevin inked him, but you knew that already

They original 200 Jizo cover is here but I only took a picture of the info.

But you can spot the Charlie Brown Jizo

The first page of Yokai is so beautiful

The original

The side by side of the first Usagi page and the first Chibi Usagi page

The creative process

. Kyle’s made a documentary on Stan that looks amazing. He hired a film crew and they went over to Julie and Stan’s home. Kyle produced, directed, edited, and did some camera work too. Unfortunately, people were having a great time and loud, so we couldn’t hear the documentary. But we did see that Grusagi got a special thanks for providing some comics to be filmed.

We hope we will be able to watch it with sound sometime soon. Right Kyle?

A closer look at David Peterson’s Usagi seasons

The draft sketch and the original Garfield variant cover

Sergio

Hector Protector - you are a big Stan fan if you have this

Beautiful cover

Frank Miller

Guardian

Stan x 2

Original thumbnails

Julie and Stan collaboration

Close up of Sergio and Stan Lee

Stan’s Mouse Guard story page

The original

I’ve never seen this before and I have no idea where it comes from

How usagi got his scar

There is a section of the museum for kids to color Usagi.

A cool photocopy of a sketch at the coloring tables

Early Usagi

Early Usagi (color)

The awards Stan has won throughout the years from the industry and his peers

Do any of you have this t-shirt?

. The very hungry Usagi original art by Eric Carle (it's not really called that)

Some of you own this (not me) but this is the original

Thanks to Grusagi friend, we took a photo with Grusagi, Julie, Stan, me, and Maichan.
The museum said this was the biggest opening they every had. Stan introduced us to the person who put together the exhibit. I asked her how she found out about Stan. She said someone sent her newspaper article on Stan that mentioned that Stan lived in Temecula. She facebook messaged Stan and got a response the same day. “They were so gracious. They invited us over to their home and let me pick out all the art for the exhibit.” If there is any chance you come down to see the exhibit, you will love it. And by seeing it you are also supporting the Sakai's and letting their town know what a greatly loved artist they have in their community.
Stan signed and sketched in Maichan’s hardcover book, which you see above.

Stan also signed the Sixth Gun
and

UY Saga Legends books I brought.
As Stan signed the Legends book he pointed out it was dedicated to Emi. And Emi was selling me the shirts, so I showed her the dedication (and she humored me

).

As mentioned in another thread, the Sakai’s put aside all the t-shirts dojo members ordered.

Julie came out of the museum after we left and handed us four jars of custom made jams (one for each of us). That's how thoughtful Stan and his family are of us fans.
On a side note: Stan knows that my parents' health has been an issue and always asked me how my mom is doing when I see him. He also asked about my daughter since he read about her having health issues here. To me, that is a pretty unique relationship between fan and artist. Throughout the years, I grown to think of Stan as a nice friend. Not in a creepy obsessive fan way. More like pen pals that don't write that often. Ha!
So thanks to Stan, Julie, Emi, Daniel for greeting us and making us feel welcome. Once again, it is a great exhibit that runs through October 22nd.