Oh shit, I was passing by looking for a picture, and then I stumbled on to oota jun'ya and I recognized the name. Then I looked in the corner for the signature of the artist. I shouldn't have been so shocked, but I was. I can't believe I forgot the given name of ZUN.
Hakurei Jinja ReitaisaiReitaisai 9, specifically.FelicitationsIn Japanese, this essentially means "congratulations"Even selling manjū is okay!?Kōhaku manjūManjū are steamed cakes filled with red bean paste. During Reitaisai 9, red and white (Japanese colors related to festive occasions) manjū were sold with this art as it's decoration.