Uruka seems to have a fetish for ruining her own perfect chances.
She just got a huge development on her end, in that she decided to study abroad. Most writers would use this chance to make Uruka more proactive and actively seek the Moe out, but not Tsutsui. She didn't change at all.
In fact, she might have gotten worse and retreated even more into her shell. That is one of the reasons why Ichika fighting back on Miku's attempted confession actually caught me off guard. Even after we got the text spoilers and knew she outscored Miku, I expected her to act the same way she acted when she found out what the bonfire handholding superstition was: full of regret and afraid she hurt her sister's feelings.
The exact opposite happened, she actually went in the offensive.I wonder if all the sisters are going to be making an active effort to get the fuutlong before he stops being study-sexual, and so 5toubun gets divided in the "study" half vs the "stop-Fuuts-from-studying-so-damn-much" half.