In the late 1970s, Miyazaki drew sketches of a film about a princess living in the woods with a beast. Miyazaki began writing the film's plotline and drew the initial storyboards for the film in August 1994. He had difficulties adapting his early ideas and visualisations, because elements had already been used in "My Neighbor Totoro" and because of societal changes since the creation of the original sketches and image boards. This writer's block prompted him to accept a request for the creation of the "On Your Mark" promotional music video for the Chage and Aska song of the same title. According to Toshio Suzuki, the diversion allowed Miyazaki to return for a fresh start on the creation of "Princess Mononoke". In April 1995, supervising animator Masashi Ando devised the character designs from Miyazaki's storyboard. In May 1995, Miyazaki drew the initial storyboards. That same month, Miyazaki and Ando went to the ancient forests of Yakushima, of Kyushu, an inspiration for the landscape of "Nausicaä of the Valley of the Wind", and the mountains of Shirakami-Sanchi in northern Honshu for location scouting along with a group of art directors, background artists and digital animators for three days. Animation production commenced in July 1995. Miyazaki personally oversaw each of the 144,000 cels in the film, and is estimated to have redrawn parts of 80,000 of them. The final storyboards of the film's ending were finished only months before the Japanese premiere date.