A fifth grader, boyish, pretty girl who is returnee who moves in from the United States to Oh-Edo elementary school. She is very good at study and sports.
She is a descendant of Issaku who is the member of Shinsengumi Hatsumeitai (invention corps),
Together with Toshi, Soushi, Kei which is the posterity of the same Shinsengumi Hatsumeitai member as her, she introduced himself an Shinsengumi and subjugates a villain. they hide real nature.
Isamii uses the "Ryu no Tsurugi (Sword of Dragon)" that they discovered from the warehouse in her grandfather's house.
Ryu no Tsurugi is usually only the handle of the hexagon, however a blade of the light emerges in Ryu no Tsurugi by shout of Isami, Toshi, Soushi.