Long silent and out of the public eye, former Prime Minister Junichiro Koizumi's recent rumblings against nuclear power are causing many to wonder if the most popular leader of recent decades is laying the groundwork for a political comeback.

The 74-year-old Koizumi has met separately with two opposition party heads — Tadatomo Yoshida of the Social Democratic Party and Yoshimi Watanabe of Your Party — to discuss his mission to rid the nation of all 50 of its nuclear reactors.

A visit to a spent-fuel disposal site in Finland following the 2011 Fukushima crisis converted him to an anti-nuclear activist, Koizumi claims.