#tldr; yes she calls him Oniichan (mostly) ... she doesn't care that hes meant to be her brother and just sees him as her prince glkask

[glasseswearingrabbitdetective]

once you ignore some bits, its honestly pretty funny; take this night scene, Akiko is reading a book we won’t comment on and giggling “guhehe~” (see clip for vocal)-  Male mc, who lives in the dorm next door, comes in to tell her to pipe down... cue Akiko jumping to hopeful conclusions which are quickly shot down. He lets her keep reading and puts headphones on, to block out her cries of “what do you mean you aren’t here to ‘do like what was in my book’!?” type things, with a sigh. 

Out of context but this way is better/safer 👍