After three episodes of finding Ai Nanasaki to be quite likeable but via a story arc which never managed to get "under her skin", so this latest arc comes to an end via two good, old-fashioned anime tropes - a school festival, followed by a hot spring.
With Tachibana and Nansaki both working behind the counter at the girl's swimming club's oden stall, we get to see all of the "drama" unfold... at least the closest a school festival can come to drama, via some tea club members and their demanding taste buds and a drunken teacher. Oh, and an out of control Gundam, but that didn't really get as much screen time as it probably deserved.
Anyhow, come the end of the festival the oden stall proved to be a huge success (it was sold out in fact), and with some time to spare at the end of the day Ai drags Junichi off into the middle of nowhere... and a secret hot spring which she just happens to know about. You can probably figure out the rest from here - Nanasaki confesses to Tachibana, he accepts her feelings, and they all live happily ever after. Probably.
With this story arc now closed, I still stick by my assertion that they simply didn't do enough with Nanasaki's character to really bring anything to the table other than her being a genuinely nice girl - after bringing her younger brother into the discussion in earlier episodes, he was effectively dropped from proceedings just as quickly, removing the only potential difficulty in Ai's life and making the rest of the arc one of incredibly smooth sailing. It also struck me that this arc never really gave us the feeling that Tachibana felt anything more than friendship for Nanasaki until he accepted her confession of love - despite his saying that he'd fallen hopelessly in love with her, his actions prior to that point never really gave that impression, with the possible exception of the diving in the pool incident last episode (another piece of drama that seemed to have been forgotten about as quickly as it was brought up).
Thus, Amagami SS continues its run of being occasionally crazy, more infrequently funny, and unfortunately not all that proficient at telling a compelling narrative of the girls Junichi meets and why they fall in love with him. Rather oddly, Nanasaki is probably my favourite girl from this show so far, even though her story was the least interesting of the bunch, but that probably says more about my preferences than the series itself.