Having failed the exam, Naru blames Keitaro and decides to take a trip of healing through southern Japan away from him but ends up repeatedly running into Keitaro, who had also failed the exam and was following the same travel route as Naru.Opting to travel together, they run into Mutsumi Otohime while on a cruise to Kagoshima.While at the Hinata Hotel, she met a young Keitaro Urashima and Mutsumi Otohime.
Plot Naru first came to the Hinata Hotel as a sickly child.
Her parents would travel with her to the onsen in hopes that the different environment would be better for her health.
Kicked out of his home for his continued persistence to get into Tokyo University and promising that he would not return until he entered Tokyo U, Keitaro makes his way to the Hinata Apartments to stay, however he soon discovers that it has become an all-girls dormitory.
Mistaken for a Tokyo University student Keitaro is allowed to stay despite mistrust from the girls, particularly from Naru.
Chasing after him, Naru joins Keitaro in the excavations; ending up getting lost in the island’s desert in search of the Turtle Civilization.
When the rest of the Hinata residents also pursue after them after learning that they had both passed their Tokyo University entrance exams Keitaro manages to send his entry ticket to the university on time to finally become a Tokyo U student.Gaining her health, Naru grew up and became a day dreamer and a poor student during Junior High School.Moving to Hinata House (now a girls dorm), Naru was given a tutor, a Tokyo University student named Noriyasu Seta.When Keitaro daydreams during an entrance exam and becomes convinced that he had failed the exam again, he boards a boat heading overseas and ends up stranded on a tropical island called Pararakelse.Meeting Seta on the island, Keitaro volunteers to work as a hired hand in his excavations of the island.Keitaro manages to gain Naru as a study accomplice and tutor.While accidentally peeping in her diary, Keitaro begins to suspect that Naru was his promise girl.While she deduces that he was not a Tokyo University student his persistance to make ammends makes him endearing and she attempts to keep his secret.Eventually the secret is discovered by the other residents and they force Keitaro to leave, however on the same day Keitaro receives a fax from Grandma Hina Urashima and becomes the landlord of Hinata House.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.