Sekirei #88 who is the female protagonist of the series. She is the first Sekirei Minato met and made a contract with, she is also at the same time Sekirei #8 Yume, who somehow is inside of Musubi.
Musubi's power is Fist type she is also number 88 which means she is incredibly strong. Musubi is carefree, rather naive and not very modest. She is Minato's Ashikabi which is her lover and her savior and for her to emerge (get more powerful) she needs DNA form another human or mucosal contact (kiss) Minato. The more Sekirei that an Ashikabi has the stronger he gets and the more that a single Sekirei kisses there ashikabi the powerful they get and they can also used there incantation which is there most powerful move or ablity. Musubi is also another Sekirei who is a former member of the Discipline Squad Yume who is number 8 she appeared once in the second season when Musubi died she stood up and stopped what was going on between all of them and then Musubi came back out and remerge or got her symbol back that is on the back of her neck that symbolizes that she is infact a Sekirei