The protagonist of the game is assigned to supervise and lead a group known as Tuned Heart, which fights crime on city streets. The members of the group are all young and pretty girls, and also experts in firearms and vehicles. Mysterious mind-controlling criminals have appeared in America, and now cities are overrun by biker gangs and other criminals. It's time for the hero to assemble his group and show those criminals who is the boss!

Tuned Heart is a turn-based strategy game with strong RPG elements. Characters are moved around on vast top-down battle fields, attacking enemies with pistols and other weapons. Characters also receive experience points and gain levels, in a RPG fashion. Beside the usual weapon-related attributes, it is possible to customize the vehicles driven by the characters, and their strength can influence the outcome of battles.