As Byakuya Kuchiki began going to the Tenth Division for training more often, he gradually realized that getting utterly crushed one-sidedly was not the most boring lesson.
"What is this?"
He watched his teacher tap his wrists and ankles with a finger. A layer of spiritual light immediately enveloped his wrists, and the light around his hands seemed to attract each other, forcing his hands together.
"A form of training!"
This was a cultivation method from the Spirit Light Wave Fist. A practitioner subjected to this seal had to constantly use spiritual power to resist the restraints on their wrists and ankles. Only then could they move freely.
In other words, the restrained person had to use their own spiritual power at all times to train it—somewhat like weight training, except it targeted spiritual power.
"What's the point?"
"To train your control over spiritual power... and the strength of your Reiatsu."
Byakuya looked at his glowing wrists and ankles. It sounded like a good training method, but wasn't this thing a little too conspicuous?
Just as he was about to point that out, Yinsen made a wiping motion with both hands, and the spiritual glow around his wrists and ankles vanished. If his hands and feet had not remained difficult to move, he might have thought the thing had already been removed.
"From now on, you'll have to keep wearing this..."
Yinsen had originally intended to say, "Only remove it in an emergency," but then he considered the young Byakuya before him. As the future head of the Kuchiki Family, Byakuya was unlikely to encounter any dangerous emergencies at all.
Still, to guard against unforeseen circumstances, Yinsen taught Byakuya how to remove the seal.
"Other than emergencies, how far do I need to train before I can stop wearing this?"