I may have been under laboring a false impression of who the main character in this series is...
Hachi-kun and all the other first-year club members in show jumping.
Minamikujou Ayame (Sayuri Yahagi). She's an old middle-school classmate of Mikage's and, in a nutshell, completely unlike any other character in the cast. In fact she sort of seems as if she dropped out of the sky and landed in the wrong show - as generic an anime ojou-sama as you could every imagine, complete with the trademark laugh. We just don't get those kind of 2D characters in Gin no Saji - so I'm going to assume she's here for more of a reason than to vamp for the camera and make Mikage look good, and that there's more to her than the walking (and riding) collection of tropes we saw this week. Sayuri is an excellent seiyuu and while there's not much any actor could do with the generic material Minamikujou had to work with in this ep, she does all she can to make her performance amusing if nothing else.
nearly disqualify himself by falling off when he spots Shingo in the crowd and loses his focus.
roots for the final rider to make a mistake and incur a penalty - which I assume is extremely bad form in equestrian sports - so he won't lose his place on the podium (which he does when the rider finishes a clean ride and beats Hachiken by a second). As for Mikage, she ends up riding Maron as well and manages a third-place performance, as well as thoroughly stealing Maron's affections from Hachiken. Seeing Hachiken struggle with his demons is good stuff, though nothing we haven't seen before - the best part of the ep for me was definitely Maron's chewing the scenery (and Hachiken's head). If the whole show jumping thing doesn't work out, I think he has a future in the performing arts.