pinoko

Pinoko is Black Jack's sidekick, a young girl created by him who is, in fact, a Teratogenous Cystoma, commonly known as a teratoma. This type of tumor can be considered a rare form of Siamese twin. She lived inside one of Black Jack's patient's bodies for eighteen years until he surgically removed her and provided her with a real body, equipped with a plastic exo-skeleton. After being rejected by her twin sister, she began living with Black Jack in his home. Pinoko assists the doctor by handling house chores and sometimes acts as an assistant during his surgeries. She often provides comic relief in the series, appearing both physically and mentally to be around five years old, although she claims to be an eighteen-year-old girl engaged to Black Jack, despite him treating her more like a daughter.