Which made the Kodokan a unique vulnerability. I’d trained there for nearly twenty-five years before powerful enemies forced me to flee the city, enemies I had, by one means or another, managed to outlast. Judo at the Kodokan had been my only indulgence of anything like a routine, a pattern that could be used to fix me in time and place. Going back to it might have been my way of reassuring myself that my enemies really were all dead. Or it could have been a way of saying come out, come out, wherever you are.

Randori, or free training, was held in the daidojo, a modern, two-storied space of four connected competition zones open to bleachers ringing the area a floor above. On any given night, as many as two hundred judoka wearing the traditional white judogi, male and female, Japanese and foreign, buzz-cut college stars and grizzled veterans, take to the training hall, and the vast space is filled with cries of commitment and grunts of defense; earnest discussions of tactics and techniques in mutually incomprehensible tongues; the drum beat of bodies colliding with the tatami and the cymbal slaps of palms offsetting the impact with ukemi landings. I’ve always loved the cacophony of the daidojo. I’ve stood in it when it’s empty, too, and its solemn daytime stillness, its enormous sense of patience and potential, has its own magic, but it’s the sound of evening training that imbues the space with purpose, that brings the dormant hall to life.

On training nights the bleachers are usually empty, though nor is it unusual to see a few people sitting here and there and watching the judoka practicing below: a student, waiting for a friend; a parent, wondering whether to enroll a child; a martial arts enthusiast, making a pilgrimage to the birthplace of modern judo.