Hinako is the youngest of the 12 sisters, and just like all of them, wants to be around her big brother when possible. She enjoys playing all sorts of games, writing cute little letters and messages, and likes storybooks, especially when Wataru is reading them to her. When she goes off to search for a missing teddy bear, even after Wataru endlessly helps her to search for him, she tells him that, "If onii-tama is with me, I don't need anything else." It really shows that even as young as she is, her playfulness expresses how much she likes her older brother.

In her story in Sister Princess RePure, we really get to see how much she adores him in a fantasy sequence where she goes on a little adventure on a rainy day and meets a frog prince, but still continues on to eventually find the one that she likes most, her big brother.