Girl A: "Are you a lesbian?"
Girl B: "Looks that way, I guess!"
Me: "A girl actually takes positive ownership of her attraction to women in a yuri story! Wonderful! In the past it would've been depicted as nothing but akogare, but here we have a girl cheerfully accepting her lesbianism! What happy times we're living in!"
Dynasty comments: "She's not a lesbian guys, it's just akogare."
Me: ಠ_ಠ
Oh the irony.
I think it's more of a debate whether or not Haruko actually was in love with Shinozaki or if she was just in admiration with her. Hard to really say whether she is a lesbian or isn't after considering that though, because of the whole deal where straight girls these days dote on each other all the time. But I think it's fair to say there is sufficient evidence to suggest as much.
And I mean, Rui pretty cleanly finds out about it and embraces it, more or less. At least, she doesn't deny it.