is a first year student at the IS Academy and Ichika's childhood friend, though they have not seen each other for six years. She has a very long ponytail. Her place of residence is home to a kendo dojo and she has been interested in kendo since she was young. Houki even competes in kendo competitions at a national level, and was the winner of the national tournament that was hosted one year before the story of Infinite Stratos began. She is part of the kendo club at the IS academy.
She pilots the Aka Tsubaki IS.