The Sea of Death was created by Mikotsuhime because she was not satisfied with her father's decision for choosing Uomihime as the successor to rule the Blue Sea. After many years of war, the Great Sorcerer Meikai finally made the decision to sacrifice his life to seal away the Sea of Death along with the residents.
- Squid (Formerly)
- Many unnamed black monsters/sea creatures
- The Sea of Death was translated literally from the Japanese term "shi no ume", which means Sea of Death. "Shi no ume" is the Japanese term for dead zones.