Seventeen-year-old Nanaka Kirisato is a high school student serious about her studies and goals in life. She frequently criticizes her best friend, Nenji Nagihara, for being a childish delinquent who spends his time fighting other boys. Then one day, after a heated argument with Nenji, she falls off a flight of stairs and suffers a brain injury, resulting in her mind reverting to that of a six-year-old. With this in mind, Nanaka's father and Nenji must keep her injury a secret as she struggles to live a normal life and grow up all over again.
Takashi Matsuyama
Sakura Nogawa
Chiemi Chiba
Yui Horie
Kenichi Suzumura
Kaori Nazuka
Tomoyuki Shimura
Asami Sanada
Mika Kanai
Sanae Kobayashi
Nobuyuki Hiyama
Saeko Chiba
Rina Nakayama
Mika Kanai
Sanae Kobayashi