A woman named Shoko, undefeated in the world of street fighting, constantly seeks greater strength. Her mentor, Koji, arrives with a challenge from a man Shoko had previously defeated. Fearing no opponent, Shoko heads to the designated underground building. In an unexpected turn, she is caught off guard and defeated by her opponent. Determined to overcome this crushing loss and eliminate her weaknesses, Shoko begins intense special training under Koji's guidance.