Through the application of the biomechanical process, it has become possible to develop new insights into self-defense and martial arts. This process tells a very different story from what we have been practicing for years. Traditional martial arts styles do not provide the necessary skills to optimally defend oneself and handle realistic situations. There is a significant difference between training in the dojo and actually applying it in practice. Therefore, KURODAIYA was developed to bridge this gap. Kurodaiya is not a mix of different styles, but has its own philosophy through the application of the biomechanical process. Ultimately, a person has two legs, two arms, and a head, and the movements are always recognizable in different styles. However, the biomechanical process indicates that it can be applied differently. Not as we would like, but as the process allows.