The episode was kinda sweet and cute but the last bit just requires too much suspension of disbelief to make it work. I don't know what kind of school would let students go to the roof of the school building which is four floors up from groud with no safety precautions. I definitely think they were gunning for the symbolic thing (ie Yuuta is the person who would make Rikka put her feet back on the ground physically and metaphorically) but the setup is just a bit of a thorn on the side. Oh well.
Also it was weird that Yuuta runs from the right side of the building to the left side but over-shoots his target and had to run back from the left to the right when the veranda of the school is clearly shown to be one long walkway with no walls in between the class rooms.
Just nitpicks really. The atmosphere of the episode is still pretty sweet.