Green Shadow sidequest - Kappamaki not being placed

[Melodia]

At the point in the sidequest where I have to put the Kappamaki on the manhole, yet no matter what Saejima just wants to enter it, which does nothing. Anyone else run into this? Can I just.....not finish it?

[Melodia]

I also can't seem to find the Rooftops memo person for some reason, checked all times of day.

[Melodia]

....and it turns out changing to night was the answer. Yeesh.
Still dunno about the Rooftops memo NPC though.

[Friendzie]

I had this quest break at the same part so that it was unresolvable, and wanted to write it down since nobody on the internet seems to have had this happened.

So, I destroyed the cucumber in my inventory after placing it the first time, because I assumed I didn't need it anymore. Shortly later I went to Sushi Gin to get Kappamaki, and it told me I needed the cucumber. I went back to buy another from the M Store, got the Kappamaki, but after that could not get Saejima to place it. I reloaded into the game, changed characters, changed time of day away from night and back, etc. No dice. I was only able to complete the quest by reloading a save from 30 minutes before, which I thankfully had. The quest worked normally when I did the same thing without destroying the cucumber and having to buy another.