Enter Kadokura Kyouko, grade school teacher, 33 years old, single. She has a gentle and caring personality and loves her job. Unfortunately she is only popular with her pupils, so her prospects of ever getting married seem… grim.<br /><br />Also enter Yamato Kazuki, university student, 20 years old, future goals = marrying Kyouko-sensei, becoming an astronaut (?). He’s been in love with Kyouko-sensei ever since she became his homeroom teacher in 4th grade. Now finally an adult and having enough money to buy a ring, he decides to propose to her and she – in some way or other – agrees to become his girlfriend.<br /><br />But even though theoretically a couple now, their teacher-student relationship doesn’t seem to have changed much. What will become of this unlikely pair?