Wash all the celery stalks and chop them into bite sized pieces, diagonally. Transfer to a mid-sized bowl and drain of all water.
Add in the rice vinegar, chili sauce, sugar, and sesame oil. Toss until all sides of the celery are covered in the sauce. Set aside for 30 minutes, returning occasionally to toss.
Enjoy right away, or store in the refrigerator for later.