In 20xx, as urban security deteriorated, "Autonomous Zone Guardians (Guardianroids)" were deployed across city blocks. In the Mousou district, a special pair was assigned—two female-type Guardianroids named Mamiita and Mia, designed with warmth and approachability. The local council restored the aging Mamiita using funds originally intended for a new model, then used the remaining budget to acquire Mia, a child-type unit. Despite differences in manufacturing era and model, both share the same manufacturer, resulting in exceptional compatibility, allowing them to form a reliable, tightly-coordinated defense team. In daily life, they assume human forms, blending seamlessly into the community, but instantly transform when duty calls. Over time, locals affectionately came to know them as the "Mother-Daughter Robots." However, the nationwide ● Criminal Mutual Pension Union, envious of their success, hires the deranged scientist Dr. Shutou Renshi to destroy the duo. Meanwhile, Mamiita's performance deteriorates due to a critical shortage of spare parts, placing them in dire straits. Can the Mother-Daughter Robots overcome the powerful robots unleashed by the doctor? Includes a 20-minute making-of featurette revealing behind-the-scenes production secrets.