Thing is, that it seems like they are COMPLETELY unaware of what love is or even dating. It's as if it is a foreign concept that does not cross their mind at any time (yet Haruka fantasizes about being married with Yuu (and Yuu thought she was gonna marry her)). They are so unbelievably ignorant (and dense) about the matter that it makes no sense, specially for high school girls.
I think it's a bit too harsh to use such absolute language. Yuu clearly has a brighter picture of what's going on with her heart, and Haruka may be dense and a bit ditzy but she absolutely knows 100% she values Yuu above anyone else, and the kisses do hold a very special meaning to both of them.
So while by no means experts in love, they have a qualified understanding of the concept and also a high level of confidence in what they think of each other.
I re-watched last episode before posting so I won't miss anything in my rant and at least at the point where anime ends, its exactly as flips described it.
Scene in the kitchen:
After Haruka and Yuu started kissing in front of Mitsuki, she jumps between them:
Mitsuki: Yuu, you haven't told Haruka-san you love her, have you?
Yuu: What the hell you are talking about?! This was something that Haruka and I decided! We have special relationship and it's fine. We're doing it because we're special.
Mitsuki: That's right. You kiss because you have special feelings for each other. Then... I have a chance, too.
Haruka: What do you mean?
Mitsuki: That's right. I love you Haruka-san. Please go out with me.
End of scene
Confession after school:
Mitsuki: I would like to hear your answer to what I asked you.
Haruka: Answer? I love you too, president Mitsuki.
Mitsuki: Huh?! What? You really love me? But you have Yuu... Oh I see! You haven't confessed to each other, have you? So, we can start going out?!
Haruka: Going at it?
Mitsuki: Going out!
Haruka: Go out and do what? (at this point I was honestly thinking, she was just trolling Mitsuki and I was waiting for punchline)
Mitsuki: Well... Holding hands... going out together... staying night at each other's houses... Well, to put it bluntly, something like dating, maybe? Kissing and such, too.
Haruka: (Thinking) The same thing I'm always doing with Yuu-chan!
Haruka: Huh? That means that Yuu-chan and I...
Mitsuki: You really don't understand what I mean by "love", do you?
Haruka: I do!
Mitsuki: You don't!
Haruka: Maybe... you're right. I'll think about it with Yuu-chan. What your love means.
Scene is little longer, but confession ends here.
At this point I was disappointed, but was still thinking. Ok, so they really have no idea what love and going out is. But it's ok, after that conversation they surly realized what their "special relationship" really is. And then this scene happened:
Haruka and Yuu sits in empty classroom:
Haruka: Yuu-chan, you did hear it, didn't you? What I and president Mitsuki talked about.
Yuu: Yeah
Haruka: I see. Hey, Yuu-chan... Do you know the meaning? The meaning of president Mitsuki's "love"?
Yuu: Onee-chan is weird because she's been studying too hard for her entrance exams!
Haruka: No, not that... I wonder what kind of love I have for you. I thought it was the same as president Mitsuki's, but I was told it's not. We hold hands, we go out together, we even sleep at each other's houses...
Yuu: We've kissed too.
Haruka: Right?
Yuu: Haruka?
Haruka: Hmm?
Yuu: I love you (and she kisses her) I thought I might figure it out if I kissed you while saying I love you.
Haruka: Did you figure anything? Let's do it again! I'll do it this time.
They kisses while saying "I love you" for a while.
Yuu: Did you figure anything?
Haruka: I feel like I kinda did, but really didn't.
Yuu: I see.
Haruka: I wonder if I'll ever figure out what president Mitsuki meant.
Yuu: Of course you will! Even onee-chan knows you will!
End of scene.
My jaw is dropped. They still don't get it after all that?!
I understand. It's comedy, it's supposed to be fluffy and funny, Haruka is a airhead, but I just can't suspend my disbelief that 2 high-school girls were so close and cared so much about each other that they wanted to be special, without knowing what love or dating is. Were they sheltered? Never saw any drama in tv, read manga or heard any of friends talking about love? I don't deny that they are aware of their feelings, but even when Haruka was fangirling about Shizuka and Kotone "They are like us!" she simply couldn't do that without common knowledge about dating and love. Or did she think they are just "special friends" like she and Yuu? Maybe in manga they become a real couple, but anime just seriously pissed me off.