TOKYO, Sept. 23 (Xinhua) -- Japan's ruling Liberal Democratic Party (LDP) officially launched its leadership race on Monday, with five candidates declaring their bids to succeed outgoing party chief and Prime Minister Shigeru Ishiba. The contenders are former LDP Secretary-General Toshimitsu Motegi, Chief Cabinet Secretary Yoshimasa Hayashi, Agriculture Minister Shinjiro Koizumi, and former economic security ministers Sanae Takaichi and Takayuki Kobayashi. Even though the ruling bloc has failed to secure a majority in both chambers of the parliament, the new leader is almost certain to become the country's next prime minister since the LDP remains the largest party. Complicating matters further, whoever becomes the new party leader must navigate the difficulties of minority governance, mend factional divides, and regain public trust. Recent opinion polls show Shinjiro Koizumi and Sanae Takaichi leading in public popularity, but insiders stress that internal party dynamics and factional support will be decisive.