While navigating the brutal prison environment, Naruto encounters new allies and enemies:

: If a prisoner ventures too far from the castle, the seal causes them to burst into flames. Key Characters and The Box of Paradise

Upon arrival at Hozuki Castle, the warden, , applies the "Fire Release: Heavenly Prison" seal. This cursed mark serves two lethal purposes:

: Mui’s son, who was sacrificed to the Box of Paradise ten years prior. Mui's true motive for imprisoning Naruto is to use the Nine-Tails' chakra to open the box and bring Muku back.

: It seals the prisoner's chakra, causing intense pain if they attempt to mold it.