
Im kinda lost rn. Kaede and Ayame are brothers right? When Shuu is referring to Kaede's love interest who is that senpai? Is shuu referring to Ayame or what?

Kaede’s love interest is Tsubaki-kun, Shuu’s senpai with a ponytail. Note that Tsubaki is actually a guy (at least on paper, they can be trans) that’s why Kaede was referring to them with suffix “kun” instead of “chan” or “san”. It’s addressed in one of the side notes that have yet to be translated.
Boy you had your chanceeeee you wasted it so leave them now alone. You knew that he was into you but you ve taken it for granted so your out of the story now bye.