I don't think he's missing anything. It's that peace of mind that's oozing from his calm personality, compared to the upthight and drama queen others, that draw little children and cats towards him. Little children and cats are never wrong :-P
He kept asking himself what he was missing in a previous chapter. I was merely responding to it after finishing chapter 19.
I know, I know. In real life, when people keep telling you there's something wrong with you, even if they're the ones who are wrong, a person sometimes ends up believing it and think he's really lacking something. That's what Heisuke did the former chapter. This manga goes a bit slow, but it's not bad at all, in the Slice of life-genre.
Heisuke will think. It was looove.