A year since becoming Tokyo governor, Yuriko Koike is riding high.

In that time, she has won over voters by successfully portraying herself as an iconoclast battling the "black box" opacity that she says has long pervaded the decision-making process in Tokyo.

Her latest accomplishment is the sweeping victory that Tomin First no Kai (Tokyoites First), the local political party Koike founded, achieved in the metropolitan assembly election last month.