There's a quest for Yui that says "I should go to the Shogukuni gardens during Noon." but when I go, she's not there.
Check it out if it's december or not, any other month she should be there
I'ts december but it's the past the festivity event, but she still isn't there did i miss a step someware or is this an incomplete section before the next upday (if there will ever be one?)
even if you finished the event, you'll have to wait for january to meet her