Information based on manga events that developed their relationship will be broken up into different categories. Because the information is manga based, it is likely there are spoilers if you have not caught up to chapter 77. Please do not send me an email complaining that I spoiled you because I warned you.

start ⋅ Teaching each other about things they were not familiar with coincidentally brought each other a little bit closer. The beach scene, of course, rose more interest in their relationship. More...? family ⋅ The loving mother and the stubborn daughter of the host club family. Although Tamaki created their family titles, Kyouya and Haruhi really do have a mother-daughter relationship. More...? friendship ⋅ Friendship is one of the most valued gifts someone can give to another. Despite their lack of interaction, Kyouya and Haruhi have a different kind of friendship.
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romance ⋅ The outing that brought Haruhi closer to Kyouya and the Host Club family provided an interesting theory. Haruhi also discovered Kyouya was not all about money and fame.
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trio ⋅ The mother, daughter, and father of the host club family. The three make an odd combination due to their contrasting personalities, but in the end they support each other rather well. More...? overall ⋅ A combintation of all the categories to create an overview of their general relationship. They may not have a romantic chance, but they balance each other well in other aspects. More...?