For twelve years, Amari Sakura was held hostage in a hidden room down in the basement by her stepfather. When a sudden blackout finally sets her free, she stumbles into an apocalyptic version of Tokyo, where she has to fight for her life playing deadly games. Chishiya Shuntaro is a brilliant doctor who hides behind cold smirks and distant walls. He built them after his childhood best friend Sakura, vanished without a trace twelve years ago, only to be found 'dead'. Her disappearance left a void he could never fill, and now he hides behind indifference, refusing to let anyone close enough to hurt him again. What will become of two childhood best friends when fate reunites them in a world where love and friendship were never meant to exist?

One excels in diamonds while the other in hearts. Let's see which is truly smarter in the end or if they both drive each other to the end.

❝ I made a promise to protect you y/n ❞ ❝That was years ago ❞ ❝You know I don't make promises to break them ❞ - After reuniting after years apart Chishiya decides to take y/n to their favourite arcade as children, however, after playing one game everything changes too quickly. Shocked to discover that once the electricity goes in their shooting game stall all the inhabitants of Tokyo and presumably Japan are gone and the electricity seems to be cut. They're trapped together in Borderland with no knowledge on how to escape.