Irazu Sandō

The is a hidden dimension within Ichibē Hyōsube's temple in the Soul King Palace, designed to test the aptitude and endurance of potential Soul King candidates.

Overview
A sacred area that not even the Royal Guard can enter without permission from the Soul King, the Irazu Sandō is "entered" by the walls and floor of Ichibē Hyōsube's temple peeling away around the candidate currently being tested, revealing a long path comprised of jumbled and irregular stones with a simple wooden torii gate at the end, flanked on either side by luminous patches of grass floating in water and hanging white shide, giving it the overall appearance of a shintō shrine. The area is filled with a constant drizzle of rain. Upon passing through the gate at the end, the candidate is brought to Senjumaru Shutara's palace.

Soul King Candidacy
Given only a wooden sword instead of their usual weapon(s), a candidate must simply walk down the path and pass though the gate at the end. However, with each step a candidate takes, they begin to feel an increasing amount of pressure on their body, making every subsequent step harder to take. This pressure either is or represents the "weight" of supporting all of existence. When Ichigo Kurosaki walked more than halfway down the path, he began experiencing strange visions of the Soul King's life, namely his separation of the chaotic void into the three realms of Soul Society, Hueco Mundo, the Human World, and the amputation of his four limbs that led to him becoming the lynchpin, which culminated in Ichigo gaining four shimmering, mirage-like pupils in the corner of each eye. A few steps away from the gate, Ichigo experienced additional visions of the original captains of the Gotei 13, was surrounded by Reiatsu of several different colors, and envisioned his body suddenly swelling up in rapid, painful growths as though about to explode, though this ended when he raised his wooden sword and channeled his power into it, creating a light that dispelled the vision, which pleased Ichibē.