Storage medium storing image processing program for implementing image processing according to input coordinate, and information processing device

A region in a displayed image is scraped away in accordance with a trail of touch with a touch pen or the like and an object showing "shavings" corresponding to the scraped-away region is generated. A display position of each of particles generated in accordance with a user's operation with the touch pen 27 or the like varies over time, in line with physical motion in accordance with actual gravity. Namely, a speed of each of the particles successively varies in accordance with prescribed acceleration (comparable to gravity) and the display position thereof is successively updated in accordance with the successively varying speed.