Hanae Yukimura, a struggling high school girl living alone, spends her days juggling classes, part-time work, and the constant weight of unpaid bills. On a cold, rainy night, her quiet life changes when she finds a soggy cardboard box in an alley, inside are two small, trembling slime creatures with a single message scrawled on the front: “ADOPTED!”

Despite barely being able to take care of herself, Hanae can’t bring herself to abandon them. What starts as an impulsive act of kindness turns into something far more magical when she realizes the slimes, Poyo and Mochi, can understand her and even try to “talk” back.