Rose pointed out to John that Kira was like his mother, and John concurred with her. You're like my mother, you just have the wrong eye color and way less affinity for pranks. So, there is that.

But John likes Kira well enough! She seems a lot more serious and... well balanced in some ways, personality-wise, than his friends and family are. But she's still willing to indulge and roll with John's more mischievous and, well, ADHD side. She'll talk about Con Air, she'll listen to him prattle on about his memories, even when his memories make no sense to him and are otherwise pretty horrifying... John would talk to Kira about just about anything. And while that is not super, duper difficult to get to that point with him... it's still important, because he is an overly sincere idiot.

Reverse?