Hinagiku Katsura is the council president, captain of the kendo club, and an unofficial school idol who garners fans from both genders at Hakuou Academy, the school that Nagi, Isumi,Wataru, and eventually Hayate attends. Before Hinagiku's sixth birthday, she and her sister were abandoned by their biological parents who had left them with a debt of 80 million yen.
Hinagiku is now 16 with the passing of time and is an expert with swords, specifically kendo. She is very capable in everything but suffers from a serious case of acrophobia. Although she tries her best at everything, Hinagiku has the same feelings as an average teenage girl.
During her first year in Hakuou she met Athena for the first time. Since then they became friends until the time Hinagiku tried to give Athena the nickname "A-tan", sparking bad memories for Athena. Since then they had been distant to each other.
She also has feelings towards Hayate but has not confessed yet. During their trip to Mykonos (in chapter 213), she revealed to Ayumu that her love for Hayate was love at first sight.