In Japanese culture, gaki is a dismissive term for a bratty child, but here it likely symbolizes . Returning to that state means shedding adult responsibilities, cynicism, and fear of failure. A "do-over" as a child is powerful because childhood is where core wounds form: missed friendships, harsh words, cowardice, or betrayal. To go back as a wiser gaki is to rewrite those moments not with perfection, but with honesty.
If "Sakuracircle Gaki ni Modotte Yarinaoshi" refers to a work similar to or is actually related to "Kakegurui" (also known as "Gaki ni Modotte Yarinaoshi" in some contexts), here's a general overview: sakuracircle gaki ni modotte yarinaoshi free