Kamijo Natsu is a homemaker living in an apartment with her husband Yoshiyuki and children. One day, she hears a rumor that her friend Komaki Rie, also married, ran away with the other man. Natsu is quite surprised because she cares about her family the most. Then she gets a phone call from Rie herself, saying she has much more fulfilling life as "a woman." In the meantime, Yoshiyuki's young subordinate Saeki Ryu moves downstairs. Natsu begins to feel the stirrings in her mind. -- NHK