so he just have a fetish for socially awkward girls
No, that's not it.
Kuroki-san being aloof is what's good.That's right... makes you just want to be by her side and snuggle up to her.And she doesn't get discouraged even if she fails...It's the gap in perception of how she looks so withdrawn but also suddenly does things that make your heart skip a beat.I get you!And what's good is that she herself is originally a quiet and reserved person.I think what makes her amazing is her bravery!Right!If I had to liken Kuroki-san to something, I guess I'd say she's like a hymn to humanity.