Really cant pick whats up in Yuzu head. That reaction in ch 9 made it seem like she also really want something more but every single chance Minami creates Yuzu just brush it off with silly remarks and overall acts as oblivious as it can be. Like, wouldnt even make sense to Yuzu already have feelings for Minami when even bathing together, naked, dont get any reaction from her.
So i rather believe Yuzu has multiple personalities or just like to play with her food way too much.