A 15-day campaign began Thursday to select a successor to outgoing Prime Minister Fumio Kishida, with a record nine candidates competing to rebuild Japan’s ruling party as its new chief in the wake of a political funds scandal and win back voter confidence. Whoever wins the Sept. 27 election, the next president of the Liberal Democratic Party will also need to tackle price hikes exceeding wage growth as well as security challenges posed by an assertive China and a nuclear-armed North Korea. The new leader is certain to become prime minister as both houses of parliament are controlled by the LD…