Wako Taira is 31 years old. She works part-time at a cinema close to her home. Her boyfriend is Fu-kun and they have lived together for three years. She has never thought of breaking up with her boyfriend, considering her age. One day, she meets high school student Yumeaki Iko. She can't resist him. Wako Taira has an affair with Yumeaki Iko.
Thirty-something Wako tells herself that she is content with life and love, but an encounter at work highlights what she lacks and what could be.
After hatching a plan to see Iko again at a showing of a film by a director they both admire, Wako wonders if this means she would be crossing a line.
Wako resolves to put Iko out of her mind once and for all, but her will is tested when he shows up to see her just as she is getting off work.
As she departs from her latest overnight rendezvous with Iko, Wako is elated. But she must face a suspicious Futa when she reaches the apartment.
Now that Iko knows the truth, Wako knows there's no turning away from confronting Futa. But he's got his mind on something else entirely.
Shocked at his newfound situation, Futa goes to his college buddies for consolation and receives advice that leads him in an unexpected direction.
Wako and Futa try to imagine the future together as the complexities from their past and present actions threaten to shatter everything.
Iko spends time with a secret admirer while preparing for the school festival. Meanwhile, Wako and Futa's relationship reaches a breaking point.
Wako settles into her new job, new apartment and newfound freedom with Iko, but the stability she seeks in life remains just beyond her reach.
Iko works with Sakaki on his film project as Wako reconnects with old flame Tsuchiya. Both encounters lead to reconsiderations and misunderstandings.
While hospitalized, Wako learns something about her coworker that reassures her. Later, Tsuchiya visits and does something that shocks her and Iko.
While Iko's schoolmates worry about his continued absence, he frets about Wako's work attendance. Her thoughts, on the other hand, are a mystery.
