While the game's co-producer Takuya Iwasaki intended to take the director's role, he was busy with other projects, so Yoko was asked to take up director's duties.[8] He also helped create the scenario and characters, as well as co-writing the script with Sawako Natori.[9][10][11] During its production, Yoko was unhappy with the amount of changes asked for by the game's advisory board.