Social Democratic Party leader Mizuho Fukushima was installed for a second two-year term Friday -- without a vote being cast.

Fukushima, a 49-year-old House of Councilors lawmaker, filed her candidacy for the party leadership shortly before 2 p.m.; no prospective opponent had filed by the 3 p.m. deadline, SDP officials said.

Having seen its Diet representation dwindle in recent years, the small pro-Constitution opposition party gained two seats in the House of Representatives election on Sept. 11, bringing its total to seven.