4koma came out one month before Pocket Monsters came out, did it not? Yet it's considered the first adaptation of the games by many.
Are 4koma's not considered manga? Lucky Star and Azumanga would like to talk to anyone who thinks that.
It was only one volume but it was a manga, and a cute one at that. It was one of the manga that actually used one of Red's designs, straight from the games too, and called him by his name.