Mince the green onion.

Prepare the shrimp by removing the vein, washing, and patting dry. Mix with sake and cornstarch.

In a bowl, beat the egg and mix with sugar and salt/pepper. In another bowl, combine ketchup, soy sauce, sugar, doubanjiang, and water.

Heat half the salad oil in a pan, pour in the egg mixture, and stir quickly to scramble until cooked. Remove and let cool.

Wipe the pan clean, heat the remaining oil, and stir-fry the shrimp until color changes. Add green onion and stir briefly. Pour in the sauce mixture and cook until slightly thickened.