Yonkoma manga, or 4-koma for short, is a comic strip style consisting of four cells of equal size, usually ordered vertically, although they can also be arranged horizontally or in 2x2 style. These strips often center around a gag/joke that is revealed in the final square. Some anime, such as Azumanga Daioh and Lucky Star got their start as 4-koma.
Your mission, should you choose to accept it, is to draw a 4-koma about any anime you wish. There are no limitations, as long as you keep within the 4-koma style. The content of the comic strip must also be within PG-level, as well. No excessive gore, swearing or nudity. (Sorry, all you hentai lovers.) Other than that, let your imagination run wild! Make the plot about anything you wish! Think of the funniest gag possible!
And, above all, have fun! :D