What makes this show better than other romance anime?

The art is terrific, I love the slow pace, there's none of the normal drama in romance stories: rivals, exaggerated misunderstandings & etc.

But most of all: character development! All 6 primary characters get it. Not a lot for most, but it's slow and natural & realistic.
These are just kids, 1st year in high school or 2nd? And they act like kids too! But they are growing up as the episodes go by. It's never "spelled out" or artificially has attention shown to it, which I find adds to the charm.

@5Cats I feel exactly the opposite lol. For me the characters feel too artificial and unrealistic. They act like kids? What kind of kid is so open about their feelings and ask for forgiveness from their friends for every little detail in their lives, like, not wanting to talk about something? If they acted like kids, like the kids I know, they would be loud and annoying, they would be making spicy jokes, they wouldn't care about their academic performances... Idk, everything they do in this show makes me think of an overly dramatic adult, not at all an adolescent.
The only character that I feel a bit more "natural" is Subaru, as I can see the way she acts as proper from a depressed adolescent... but frankly, I fail to understand why she is so depressed, like, a random kid told her he didn't like her hair colour 10 years ago... and... that's it?

@PurpleMario Subaru is depressed because she really loves Waguri and possibly thinks of herself as a lesbian although very much I doubt she is. That would cause major depression, since Waguri is 100% het. ( I ship Subaru and Ayato Yorita, although Saku may be the most obvious choice)

The boys in the show mess around with each other quite a bit. Nothing out of place there.

Highschool kids "don't care" about test results? News to me! And there was the added pressure of not being allowed to participate in sports day if they failed, too. So normally they wouldn't, but that drove them to care. That teacher was no slacker, eh?

Rintaru IS far too serious for a young person! But that's who he is, he's been that way since he was very small.

Think of the anime (any high school anime!) as "snapshots" of their lives. The daily grind of BORING stuff is not shown, it would take up 7-8 episodes out of 12! No one needs to re-live that! (shudder) A good story shows the interesting parts! Good OR bad, or both, depending on the story. Here we get to see the parts where the 6 of them learn and grow together. 10/10 from me!
It ranks up there with, although is completely different from, Toradora. More recently Honey Lemon Soda or Skip to Loafer too.
Cheers!