A new teacher arrives at Furinkan High School. This instructor is said to be a formidable teacher of great repute, having previously subdued three delinquent-ridden high schools. However, the person who actually appears is an adorable girl who looks like an elementary school student, giving no hint of such a fearsome reputation. Yet, contrary to her cute appearance, she (Ninomiya Hinako) is a martial artist possessing a terrifying ultimate technique called the "Indiscriminate Combat Ultimate Secret Technique: Good Child's Exercise Number One: Happō Goen Zan." The Happō Goen Zan is an ultimate finishing move that utilizes Hinako's unique constitution as a battle aura-absorbing physique. By passing a five-yen coin's hole towards her opponent, she completely drains their battle aura, rendering them unable to fight without even engaging in combat. Happōsai, who reveals the secret of Hinako's battle aura-absorbing physique to Ranma, declares that if Hinako is left alone, disaster will eventually befall Ranma himself. To protect the Indiscriminate Combat style, he orders Ranma to defeat Hinako. He then proceeds to teach Ranma the location of the pressure point that can nullify the battle aura-absorbing physique.