This is a love story between 29-yr-old Yuki and 20 yr-old Doku. The story begins when Yuki, an ordinary OL, traveled to Vietnam and was rescued by a quiet young man, Doku. After she returned to Japan, she quit her job and decided to become an Japanese teacher. On the first day of her class, she was surprised to find out that Doku was also in her class. Since it was the first day (and first time) of her teaching, she was too nervous and was laughed at by the students. As she started to cry in front of the class, Doku stood up and walked toward her, smiling and telling her: "Please show us your courage".