Nanaka 6/17
Genres: Comedy, Drama, Romance, Slice of Life
Type: TV, Episodes: 12
Aired: Jan 9, 2003 to Mar 27, 2003
Studio: J.C.Staff
Source: Manga
Rating: PG-13 - Teens 13 or older
Synopsis:
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. 

(Source: ANN)