After forming Key, Maeda worked on the music and scenario for their first title "Kanon" released in 1999, which proved to be very popular in the adult game market in Japan. Beside Maeda, the majority of "Kanon" scenario was written by Naoki Hisaya, but he quit Key shortly after "Kanon" was produced. Following this, Maeda wrote most of the scenario for Key's next title "Air", along with again working as the lyricist and one of the composers for the music featured in the game. After a period of four years in 2004, Key released their third and longest game "Clannad" where Maeda did a vast amount of the writing for the game; in all, Maeda put in around 75% of the work that went into the creation of "Clannad". Also in 2004, Maeda began writing his first manga entitled "Hibiki's Magic", which was first conceived as a short story he wrote as a student. In 2005, Maeda worked on the scenario and music for Key's fifth game "", followed by Key's sixth title "Little Busters!" released in July 2007 which he also worked on in regards to the scenario and music.