Set on the planet Yietta, whose colonists make their living by exploiting the planet's unique liquid-gas oceans, Plastic Little begins as the Yietans are finally about to pay off their debts to the Galactic Federation. Unfortunately, there are those who would rather not let Yietta slip through their fingers...

Enter Tita, 17 year old captain of the Cha Cha Maru. Together with her crew, Tita specializes in capturing Yietta's exotic life forms for intergalactic pet shops, but through plain bad luck she finds herself, instead, at the core of a sinister plot to take over Yietta! By rescuing 16 year old Elysse from the very clutches of the military, Tita puts the lives of both herself and her crew in mortal peril... but a girl's got to do what a girl's got to do!

As the plotters mobilize their forces in a desperate bid to retrieve Elysse, whom they believe possesses a vital computer code, Tita must play a dangerous game of tag with an entire army of professional killers! It's Cat and Mouse on a planetwide scale, with one crucial difference: Mice don't shoot back, but Tita's does!