J League: The reason why J2 and J3 are called “demons” and “swamps”
Speaking of the J League, many people probably think of the top league, J1. However, the J League also has lower leagues called J2 and J3, to which many clubs belong. However, once a team is relegated from the top league, it becomes difficult to promote from the lower leagues. That's why J2 and J3 are called swamps or demonic regions.