Karasuba

"Now listen here Musubi, you have to toughen yourself up so you'll keep getting stronger and stronger, just like she was. I want you to become even stronger but I also want to make sure we keep our promise to each other: to become the last two standing and then we can fight each other till the end. Until that happens, let's just keep having fun killing Sekirei."

- Karasuba to Musubi

Karasuba is one of the main antagonists of Sekirei and among the most powerful of Sekirei.

History
Karasuba is known as Sekirei number 4 and leader of a group called the 3rd generation Disciplinary Squad.

Personality
She has a great hatred for the world and has a rivalry with Sekirei number 8 Yume. She finds enjoyment in killing other sekirei which is her way of relaxing. She mantains a cold demenor but gets excited by the idea of fighting strong opponents. She has no regard for life but She will stop herself from killing her rival Yume who rest's inside Sekirei number 88 Musabi to keep a promise she and Musubi both made: to keep fighting till they are the last two Sekirei. Karasuba shows Patience, honesty and encouragement when she's around Musubi.