Jukai (樹海; Lit. "Sea of Trees") is the realm where the Shinju resides. It has distinctive colors, and the only way to access it is to be a Hero. In the year 301 DE, it is no longer possible for anyone to access the Jukai, as the Shinju has perished and the Yusha System is therefore not usable anymore.
The Jukai bears an incredible difference than the normal world. Being another layer of reality, the ground is covered in vines and has a rainbow color scheme, ranging from purple to green to teal. The land itself has a leaf pattern on it. In the first years of the Divine Era, the Jukai was a small plant wrapping around buildings. Three hundred years later, it was as vast as it is encasing everything leaving nothing visible.
The Jukai is connected to the real world-so if any damage happens there, damage happens in the real world. This is shown by a fiery red substance consuming the area around them.
After the attack of the heavenly gods were destroyed, the Jukai expanded over humanity's lost land with an aurora of flowers and with the Shinju perishing, the ivy and plant matter barrier was gone along with the gods.
- Main Article: Shinkon
During the events of a shinkon, a piece of the Jukai will send the wife of the Shinju towards him. If the heroes try to intervene he will use the jukai to his advantage by using the roots to stop the heroes.