Dark Mint emerges as an artificial creation of the antagonist Shadow, forged through a green Mirror Crystal and Cure Mint's power. This genesis occurs exclusively within the Mirror Kingdom's events, where Shadow deploys dark clones to challenge the Pretty Cure team and secure the Dream Collet. She mirrors Cure Mint's physical traits yet champions a diametrically opposed worldview.

Her personality radiates arrogance and pessimism. She derides protective power as inherently useless—a symbol of frailty—and weaponizes offensive variations of Cure Mint's defensive abilities during their clash to prove this conviction. She maintains unwavering respect for Shadow as both creator and sovereign.

Dark Mint's evolution ignites in conflict with Cure Mint. When Cure Mint declares a heartfelt resolve to protect Dark Mint herself, this shatters Dark Mint's foundational beliefs. The confrontation culminates in Cure Mint physically embracing her dark counterpart, triggering visible tears in Dark Mint that mark a transformative perspective shift and the dawn of reconciliation.