TOKYO (Kyodo) -- Shinji Ishimaru, who placed second in the Tokyo gubernatorial election in July, has expressed eagerness to establish a new regional political party ahead of next summer's metropolitan assembly election in Japan's capital.

Ishimaru, a 42-year-old social media-savvy former mayor of a city in Hiroshima Prefecture, ran in the gubernatorial race as an independent and garnered more votes than Renho, a popular female politician backed by Japan's largest opposition party.

"If you want to become a metropolitan assembly member, you should start preparing," Ishimaru said on a YouTube program released Tuesday, pledging to recruit candidates for his envisioned party, the details of which are likely to be announced in December.

A relative unknown in Tokyo before official campaigning for the July election began, Ishimaru boosted his profile through social media, gaining popularity among voters not affiliated with a party.