Hikari is the protagonist of the story. She holds the 2nd position in school for having the best grades. Self-proclaimed as Kei Takishima's greatest competitor, she is determined to beat him in any kind of competition. Stubborn, proud and hot-headed, Hikari never backs down from a challenge, especially one from Kei, because she is constantly looking for an opportunity to surpass him, though has never done so. A kind girl who always worries about others, Hikari sometimes lacks common sense. She is good at sports and academics, but she is very bad at teaching, cooking, and sewing (any other domestic work). Although she can handle her own in a fight (often against boys), Kei, nonetheless, gets irritated whenever she puts herself in danger. Although Hikari is rather sensitive to others, she is quite dense when it comes to love. She is oblivious to the romantic feelings Kei has for her, though everyone else knows that Kei is in love with her. In volume four Hikari begins to fall in love with Kei, though she does not realize it until volume six.