Gov. Yuriko Koike's upstart Tomin First party scored a sweeping victory Sunday in the Tokyo Metropolitan Assembly election, dethroning the Liberal Democratic Party and damaging Shinzo Abe's prospects for winning another term as prime minister.

With 49 seats, Koike's Tomin First no Kai (Tokyoites First) became the largest party in the 127-seat assembly.

"The result is much better than we had expected," Koike said in an interview on Fuji TV. "Our candidates are all fresh, and this new lineup will make the assembly something completely different."