Atobe doesn't take people for granted. It's not his way.
Kabaji, for instance, carries his bags (as well as sundry necessities such as his singles two player), serves as a reliable practice partner and competition regular, and provides a comfortable surface to lean and doze against during long limousine rides. He obeys Atobe's every order unhesitatingly, without question.
In return Atobe pays attention. He knows, though Kabaji says nothing and demonstrates little, and others overlook. It doesn't take any effort, because he wants to.
In someone else it might be termed gratitude.
His father is a man who had to prove himself before the world. Atobe is a worthy heir to the throne: he passed every test with flying colours, for as long as he can remember. But some sets of expectations are lower than others, and Kabaji wants nothing from him that he can't deliver as easily as breathing. Nothing, other than being.
If he were given to introspection he would know this means he tires – sometimes. But Atobe does not waste time examining the irreproachable.