Fundoshi-ai -

It is worn to allow freedom of movement, often seen in festivals (matsuri).

Kenji fed thousands of hours of 3D motion data into his algorithm, creating a digital twin—the Fundoshi-AI—that simulated human movement in a virtual, unconstricted state. The Unexpected Breakthrough fundoshi-ai

As the cold, icy wind whipped around him in the temple grounds, Kenji realized the AI was right. The tight, supportive binding allowed him to breathe deeply and move with incredible agility despite the freezing temperatures, making him feel like a samurai of old, focused solely on his goal. It is worn to allow freedom of movement,

"It’s not just a strip of cloth, Kenji," his elderly mentor, Master Sato, insisted. "The fundoshi was designed for maximum movement, freedom, and health. It holds the pelvis upright, freeing the hips and lungs. It is an engineering masterpiece of the human body, not just a fashion choice". The tight, supportive binding allowed him to breathe