Hozuki Castle was not located in the Land of Grass.
It stood on an island out at sea.
The island's edges were lined with towering cliffs, with treacherous waters below.
The only way onto the island was by boat.
Although Hozuki Castle was merely a prison, most of its inmates had special identities.
The people of Hozuki Castle had made quite a fortune from them.
Many people who came here would never leave for the rest of their lives, and Hozuki Castle gradually expanded.
As the number of prisoners increased, so did the guards and their families and friends.
Hozuki Castle grew larger and larger.
However, Mui's Fire Style Sealing Technique was exceptionally suited for defending this place.
Anyone bound by Fire Style: Heavenly Prison simply could not gather Chakra.
Although Fire Style: Heavenly Prison did not work in water, the surrounding waters were deep and swift.
Anyone who jumped in would drown before they could gather Chakra.
Combined with his status as the gatekeeper, Mui had already taken the position of lord of Hozuki Castle.
At this moment, Mui was leaving the prison cells, while a guard behind him dragged along a prisoner.
Before long, they arrived at a secret room underground.
Mui waved the guard away.
Then, he pressed a mechanism beside him and entered a hidden door nearby.
The place resembled a biochemical laboratory, with all kinds of bottles and jars surrounding it.
At the center stood a stone bed, with four large lamps overhead.
Mui casually tossed the unconscious prisoner onto it and secured his limbs.
"Click, click, click..." The sound of stone shifting came from nearby.
Mui turned to look at Muku, who had entered through another hidden door.
"Where's Ryūsetsu?"
A faint smile appeared on Muku's face. "She went to buy something. She'll be