A visual novel/game studio under Visual Art's, known for making dramatic and plot-oriented visual novels.
Kanon was Key's debut release, which combined an elaborate storyline, a modern anime-style drawing style, and a musical score to help set the mood for the game.
Key's second game was Air. It had a similar if not more complex storyline to Kanon and a more thorough gameplay.
Key's third game was Clannad and is their longest work, comprising of over 62,800 text lines. The game consists of two story arcs in the game: the School Life arc, and the After Story arc (which is set 10 years after the School Life arc).
Both Kanon and Air were originally produced as adult eroges games(only Clannad was not), but had non-ero console ports released for the Dreamcast, PS2, XBox 360 and PSP.
Three of Key's works, Kanon, Air and Clannad, have been made into anime. Key supervised the production of these anime titles while working with two animation studios Toei Animation and Kyoto Animation.