Hmm... What a hella fast and abrupt confession from senpai! Judging from the title, I don't think things are gonna go smoothly with them transitioning into a relationship. That last panel/thought shows Yuu clearly confused about the sudden development.
Can you imagine? An hour ago, you spill your guts out to your trusted senpai and then RIGHT AFTER you had a hard time rejecting someone, same senpai confesses to you? I don't think Yuu is gonna just be like, "oh lol okay! let's date!" Kouhai is gonna make senpai WORK for it and I can't wait to see it happen.
(On a side-note, these character designs remind me of Yumi and Sachiko from MariMite but then again ~50% of yuri series I've read share that, haha.)