Smilesoft
Smilesoft is a Japanese company that developed RPGs and formed in 2000. They went out of business in 2003, only three years after they first formed. All games that they released were Japan-exclusive.
Games developed
Keitai Denjuu Telefang, often shortened to Telefang 1, was the first game that Smilesoft developed, and was released on 3 November 2000. It is a monster turn-based RPG, with monsters called Denjuu. The two versions of it are Power and Speed version.
It is also the most notable and popular of all the games Smilesoft has developed, due to Chinese bootleggers releasing a bootlegged English version of it, which had many glitches. It was released under the name of Pokémon Diamond and Jade, which led many to think it was a Pokémon ripoff, leaving bad impressions on the game.