The battle is officially on -- Liberal Democratic Party President Shinzo Abe vs. Democratic Party of Japan leader Ichiro Ozawa.

While Abe is set to become the new prime minister Tuesday in a Diet vote, Ozawa was officially reinstalled as DPJ head at an extraordinary party convention Monday after an uncontested leadership race.

At a glance, the power balance obviously favors Abe of the ruling party. But analysts say the largest opposition party is gearing up efforts to knock the LDP off its throne.