assuming its ZUN on the stamp (due to the hat and the beer), shou is portrayed as sun wukong due to her pose (and maybe qualifying for shou's missing pagoda pool?), unsure of whos in the picture with alice/marisa, and im also assuming its koishi and satori beside okuu/orin but its not defined so left it as is
The ones with Alice and Marisa are Shinki, Yumeko, Mai, and Yuki, and the two with Okuu and Orin are definitely Satori and Koishi, you can see Koishi's hat and Satori's pink hair. Added them to the tags.
Additional details: Merry and Renko are in the Chinese city of Shanghai (you can see Shanghai's skyline including the Oriental Pearl). That panel is also shown behind Aya in her newscast.
Seija posting the "Luck" (福) sign upside down, which is ironic for her, because they are supposed to be posted upside down in real life.
Kaguya's room has a sign that says "欧" and "SSR", referencing the "SSR" rarity cards/collectibles in gacha-based games like FGO, and the shorthand for "欧州橙万岁" (lit. "Long live the European Orange), a prayer(?) that Chinese (and Taiwanese) players of gacha games would shout just before playing the gacha in hopes for getting really good pulls (such as the aforementioned SSR cards/collectibles).
I've scoured the image all-over with my eyes time and time again, and I've come to the conclusion that the hand giving the otoshidama to Reimu must be Rinnosuke's, because he's in the tags and I simply can't find him anywhere here.
I've scoured the image all-over with my eyes time and time again, and I've come to the conclusion that the hand giving the otoshidama to Reimu must be Rinnosuke's, because he's in the tags and I simply can't find him anywhere here.