Hinagiku Katsura is the current student council president, and kendo club president at HakuÅ Academy, the school that Nagi, Isumi, Wataru, and eventually Hayate attends. She is fifteen and is an expert with swords, specifically kendo. She speaks as many as 17 languages, and is an expert linguist. She first meets Hayate when he gets lost on the huge HakuÅ campus and ends up rescuing her. She had been helping a baby bird who had fallen out of its nest, but due to her fear of heights, had become stuck without her realizing it. Hayate ends up helping her down the tree, and then promises that he will come help her should she ever call for him. In gratitude, she invites him to the top of the school's clocktower, where only student council elites are allowed. She allows Hayate to call her by her first name and also seems to be infatuated by Hayate and his attractive personality. Her family, while shown to be well off in volume 8 (chapter 76), does not show any signs of being rich in comparison to much of the cast.
However, in Volumes 9 and 10, it is revealed that Hinagiku suffers from a past nearly identical to that of Hayate's - she, along with her sister, had also been abandoned by their biological parents who left them with a debt of 8 million yen (approximately 1 million US dollars [exactly $985,161.012]) shortly before Hinagiku's sixth birthday. Following this, her sister, Yukiji, managed to pay off the debt (albeit through what the manga depicts as rather dubious means) and the two of them went to live with the Katsura family, as Mr. Katsura had been Yukiji's elementary school teacher. When Hinagiku finally sees the beautiful view from atop the clocktower on the night of her sixteenth birthday with Hayate's help, though, she finally realizes that she actually loves him. She had been afraid of admitting this to herself because she was scared that she would forget about her past if she fell in love with him. She likens her feelings to the scenery atop the clocktower: she had been unable to see them because she had been too scared to. When Hayate asks her if she's still scared, she replies that while she is, it's not a bad feeling, which is a possible response to both her fear of heights as well as her fear of abandonment. Hinagiku's problems are not over yet, however; in Volume 8, when Nishizawa and Hayate were staying over at Hinagiku's house, she promised Nishizawa that she would support her in her relationship with Hayate. Now having fallen in love with Hayate herself, she must come to terms with her feelings of betrayal as she tries to find a way to tell Nishizawa about her feelings. As such, she publicly tries to help Nishizawa get closer to Hayate, but finds herself feeling saddened whenever she does so. She also helps Hayate get closer to Nishizawa, taking on an almost motherly role as she feels exasperated by his slip-ups time and time again. Although Nagi seems convinced otherwise, Hayate himself doesn't seem to think that Hinagiku could have feelings for him, which leads him to saying things that hurt her as well (such as in volume 12, when, after Hinagiku said that a good White Day gift would be biscuits, he remarks cheerfully that he could buy the basket of biscuits on display that Hinagiku had been eying to give to Nishizawa). Later on in the series, after many interruptions, Hinagiku manages to confess her love for Hayate to Nishizawa in order for her to help clear her conscience. Upon hearing the news, Nishizawa cheers up Hinagiku, leaving her confused. She explains that although her feelings may not be returned, she is content to be with Hayate nonetheless and encourages Hinagiku to try her best, provoking a competition between the two friends.
Hinagiku is sometimes referred to as being rather masculine for a girl by other characters in the series. This is exemplified on Valentines Day in Volume 7, where Hinagiku is given a lot of chocolates by female admirers. Miki suggests this is because Hinagiku is seen as being "cooler" than the boys, and the fact that she was rather domineering at a younger age. Her athleticism, competitiveness, and leadership position all also probably contribute to this view. This is similar to how Hayate is seen as being rather feminine, and wound up giving chocolates to girls on Valentines Day when it was supposed to be the other way around. In addition, on Valentine's Day, she had considered giving Hayate chocolates as well, but ate it herself because she didn't want to add to Hayate's troubles after Nishizawa had already given him chocolates as a way of confessing her feelings to him a second time. Thus, on White Day in volume 12, she regrets not having given him any chocolates, as he would feel no obligation to return the favor as a friend.
The anime has given her pink hair, which corresponds with her hair color in most of the manga, except on the color page cover of chapter thirty-seven where she has strawberry orange hair. The hair clip she is always seen wearing was a birthday present from her real parents. She met Athena prior to meeting Hayate a year before.
When Hinagiku tries to confess her love to Hayate, he surprises her with his feelings, telling her that the one he loves is none other than Athena and that he needs to confess his feelings to Athena. Hinagiku advises Hayate to pursue his feelings and not be hesitant. When she goes back to the mansion she's staying at, Hinagiku breaks down in tears, whilst trying to accept the fact that Hayate loves someone else. In later chapters we see that Hinagiku has decided to help Hayate and the others when King Midas made his move and attacked the hotel where the others were staying. She goes to Athena's mansion to help Hayate defeat King Midas and rescue Athena. Once Hayate and Athena are reunited (while displaying great signs of affection for each other), Hinagiku leaves in tears trying to give them some privacy. The next day, after the Athena conflict is resolved, she learns from him that Athena turned him down, but Hayate escapes before she is given a chance to pursue the topic.
