Yonmi

"Those four are a difficult bunch to manage. However...their debt is enough to allow them to complete their job flawlessly. If you move even an inch closer to the noble houses of Soul Society...you will have to go through them. Trust me, their combined might is enough to, very likely, topple me."

- Shunsui Kyōraku commenting on the Yonmi.

The Yonmi (四海, Four Seas) are a small group of individuals consisting of four Souls who have gone through Shinigami training in one of the four methods of the Zankensoki, each becoming a master in their respective field. They are in charge of the overall protection of the Four Great Noble Families within the Seireitei. Their technical leader is the Captain-Commander of the Gotei 13, whom is currently Shunsui Kyōraku.