 The title of the films second half, "Magokoro wo Kimi ni"  (Sincerely Yours), comes from the title of the Japanese version of  _Charly (1968)_ (qv), which was based on Daniel Keyess "Flowers For  Algernon". "Magokoro wo Kimi ni" was reportedly the title given to  the first edition of Keyess story when it was released in Japan.