TOKYO Shigeru Ishiba became Japanese prime minister on Tuesday, seeking to restore the ruling party's popularity and tackle a demographic crisis, a lacklustre economy and fears over China's military build-up. Ishiba, 67, says he intends to call a general election for October 27. He won a tight race on Friday to lead the Liberal Democratic Party (LDP), which has governed almost constantly for decades. Japan 's parliament, where the LDP has a majority, approved Ishiba's appointment Tuesday,