Cut the green peppers in half vertically and finely chop.
Thinly slice the onions.
De-shell and devein the shrimp, sprinkle sake, and let sit for a while.
Coat the shrimp in katakuriko.
Heat vegetable oil in a pan, cook the shrimp on both sides, and temporarily transfer to a plate.
Heat more vegetable oil in the pan, saute the green peppers and onions, and sprinkle pepper.
Reduce to low heat once the green peppers and onions have softened, return the shrimp to the pan, add in the ketchup and evenly coat everything in it, and it is done.