Takehito, a dentist, invites a patient to Bali. His friend Ryuta derails this plan. The two men head to Bali, meet Takehito's ex Aya and a woman Chigusa. Chigusa and Takehito sleep in the same room. He doesn't see her off. They meet again.
Takehito's dad is after him to get married. He asks a girl from a hostess bar to pretend to be his fiance. Chigusa scares the girl off, and then goes to meet his dad. She tells them her mom raised her, and she is determined to be happy.
Aya keeps failing auditions, and is working at a bento shop. Chigusa tells Taketo to go to Aya, so he tries again. Aya eventually accepts him, but when Chigusa shows up at Taketo's place, she is shocked to learn Aya is there.
Taketo, Chigusa and crew catch Aya kissing a fashion designer who might hire her. Chigusa tells Taketo to forgive Aya, so he tells Aya to stop. The next day, Chigusa sees Aya kissing the designer again. Taketo is blissfully unaware.
Otomo invites Chigusa to meet his parents. Taketo fights with Aya at her fashion show, returns home to a surprise birthday party. Chigusa confesses to Otomo that she slept with Taketo. Aya admits to sleeping with the designer.
Taketo's dad owns up to having lost his job. When the power goes out, Chigusa calls Taketo to come keep her company. Aya announces that she is going abroad to model, leaving Taketo free.
Taketo, Chigusa and Ryuuta head to a hot spring. Taketo learns his dad got Aya to break up with him. Taketo gets Chigusa from her work, takes her to Aya, telling her he intends to be with Chigusa. Chigusa is happy but worries.
Miyuki tells Ryuuta she might be pregnant with his child. He avoids her, but eventually tells her he's ready. Taketo tries to woo Chigusa to bed. She is plagued by doubts that he isn't serious or still loves Aya. He asks her to move in.
Taketo's dad and Chigusa's mom invade their love nest to shout at the other. A letter arrives from Aya. Chigusa can't resist the temptation to read it. Taketo becomes irritated, and storms off, but returns the next morning to apologize.
Chigusa goes swimming. A lifeguard suggests she become one. Taketo criticizes the idea, but apologizes. When Taketo's dad falls sick, Chigusa comes to care for him. She heads out on a five day trip to train to become a lifeguard.
Taketo's friend offers to finance an office if he returns to Hakata. Taketo invites Chigusa to come with him to meet his mom. Aya lies to Chigusa, making out as if she had slept with Taketo. Chigusa doesn't go, and ignores his calls.
Aya fesses up to tricking Chigusa. Taketo brings Chigusa to meet his mom. They get along, but Chigusa leaves to swim. Taketo finds her at the pool. Chigusa: "I hope to become a woman you'd run after." Taketo: "You already are.'
