Koichi Ninomiya serves as the Fuku-Kanchō (Vice Grandmaster) of Enshin Karate and is the son of its founder, Joko Ninomiya. He has trained in Enshin Karate since childhood, receiving direct instruction from his father and developing a thorough understanding of the Sabaki method through decades of consistent practice, competition, and teaching.

An accomplished martial artist, Koichi won the 2008 World Sabaki Challenge Middleweight Championship, demonstrating effective application of Sabaki principles at the highest level of full-contact competition.

As a senior instructor, Koichi has taught seminars, demonstrations, and classes in numerous countries worldwide. He is widely respected for his ability to teach youth students, creating a structured and engaging learning environment while connecting with young practitioners through clear, age-appropriate instruction. Through his work, he plays a key role in maintaining the technical standards of Enshin Karate while supporting its continued development and global growth.