Toshifumi Fukaya

I practice and teach from the intersection of two traditions — classical Japanese martial arts and science-based bodywork. My work is built on a simple premise: the body already knows how to move well. The work is not to add, but to subtract.

Martial Arts

I have trained in classical Japanese martial arts since my teens, beginning with karate before finding my way to koryū swordsmanship. I am the 12th-generation master and Tokyo branch head of Niten Ichi-ryū Genshinkai — the sword school of Miyamoto Musashi, formally known as Hosokawa Family Traditional Heiho Niten Ichi-ryū.

The school maintains the full dual-sword curriculum, from foundational forms through the advanced Gohō no Tachi sequences, unified by the principle that every technique is a two-sword technique — even when only one sword is drawn.

Bodywork Research

Drawing on the martial tradition as a foundation, I developed JINEN Bodywork — a practice that integrates classical body mechanics, anatomy, and modern neuroscience into a coherent system for understanding and refining how we move.

JINEN takes its name from the Japanese principle of jinen (自ずから然り) — natural arising, what happens of itself. The practice centers on restoring the body's own intelligence rather than overlaying it with external correction.

I hold a master's degree from Kyushu University and the qualification of Shintai Kinsei-shi (身体均整師 — Body Balancing Practitioner). I run instructor certification programs for JINEN Bodywork, as well as an ongoing online practice community.

What Unifies the Two

Classical swordsmanship taught me that power does not come from muscular effort, but from structure — from ground reaction force traveling through a relaxed, connected body. Modern neuroscience calls this feedforward control, tensegrity, and body-remapping. The vocabulary is different. The observation is the same.

This site is an attempt to think through that convergence — in writing, in practice notes, and in the ongoing work of building a teachable system.