I'm just so glad author took this path, communication is key. Also good to see Kanako got in a bit of a crisis herself because she still needs to sort her feelings, if even if Ueno stay away from Chisaki there's no romantic love between her and Kanako, she'll always remain desatisfied with that.
Even if nobody ends up together, they can all get out of it as better people
Funny bit: just thought that Manaka is trained in martial arts an seen before, so she can satisfy Ueno if he's fully honest with his preferences :V