Naru developed an unrequited crush on Seta and went from a laid-back dreamer to the number one exam student in Japan.After Naru entered High School, Seta left to go overseas, but Naru promised him that one day she would get into Tokyo University.Her frequent and eventually predictable response to anything Keitaro may do to irritate her is to physically beat him senseless, usually sending him flying into the stratosphere with what the dormitory residents dub "the Naru Punch".She often wears thick glasses, sweaters, and braids when going to cram school to deter attention from guys, whom she classifies as pointless distractions.Naru is reliable, kind, caring, and responsible, In contrast, Naru is characterized by her short temper and physically aggressive nature when irritated.
Her parents would travel with her to the onsen in hopes that the different environment would be better for her health.
Discovering that she, also, was on a trip of healing after having failed her Tokyo University entrance exam and concerned over her anemia, the pair include her in their travel group to see her home to Okinawa.
During the trip Keitaro and Mutsumi exhibit uncanny similarities and discover many similar interests, so much so that Naru begins getting jealous over their compatibility.
The unofficial "leader" of the girls living at the Hinata House, Naru possesses both physical beauty and intellectual brains.
She is the most reliable and compassionate member of the household, and will stick her neck out for anybody that needs help, even people that would initially dislike her.
Keitaro manages to gain Naru as a study accomplice and tutor.