Seifuku

The Seifuku (住む王 The Eight Kings) is the term used to identify the eight strongest pirate captains that cross the Red Line and make it to Sabaody Archipelago with a bounty over  300,000,000.

The World Government feared that a meeting between these eight captains could cause a huge dilemma, in which they heavily surveyed Sabaody Archipelago in case of that. It was during the Gemini Tournament that the Eight Kings finally meet all of each other, causing the rivalry to begin between the eight different crews.