Although some aspects of the plot differ between the film and the drama, the main story line is the same. It is the story of Mika, a schoolgirl, and the dramatic transformation she undergoes when she meets Hiro, a student also at her school who is keen to call her his own. Throughout both adaptations, the unlikely couple struggle to deal with a jealous vendetta from Hiro's ex-girlfriend, Saki, disapproving parents and an unplanned pregnancy. Shortly afterwards, Hiro discovers that his health is deteriorating and makes the painful decision to break up with Mika to keep his terminal illness from causing her pain, but continues to follow her whereabouts through his highschool friend, Nozumu. Mika eventually forgets Hiro with the help of Yu. Through a chance meeting, Hiro's condition is revealed to Mika and she makes a difficult decision to leave Yu to go to his bedside. Having Mika back, Hiro is determined to fight his disease and begins to improve. But during a routine checkup, Hiro's condition makes a turn for the worst and he exchanges goodbyes with Mika and his family for the last time.