The practice is designed as "whole body breathing" where the mind leads the body.
At the end of the exhale, Ki should continue to extend infinitely like a fading note.
Inhale from the tip of the nose until the body is naturally saturated with breath. Ki Breathing by Koichi Tohei Sensei
Maintain purpose and control throughout the breath.
The breath should make a distinct but barely audible sound (often described as an "a" sound rather than "h" to better engage the diaphragm). The practice is designed as "whole body breathing"
(Ki-no-kokyuho) is a foundational practice developed by Koichi Tohei Sensei , the founder of the Ki Society and Shin Shin Toitsu Aikido. Unlike labored deep breathing, Tohei Sensei’s method emphasizes naturalness and the unification of mind and body to activate one's "life power" and maintain harmony with the universe . Core Philosophy
Tohei Sensei taught that our lives are part of the "universal Ki" and that breathing is the primary method to keep this conflux unimpaired. Maintain purpose and control throughout the breath
Correct breathing is impossible without a natural, stable, and relaxed posture, which Tohei called "the posture of mastery".