After he decided to fight the resolution of no confidence against him and dissolved the Futaba-machi Assembly, he was holding meetings with his townfolks.
One such meeting was to be held in Koriyama City in Fukushima Prefecture where some of the Futaba residents have been living in the temporary housing. But Mayor Idogawa, 65, fell suddenly ill with dizziness and severe headache, and he was hospitalized on January 20 to have medical tests done.
On January 23, he asked to resign.
If you haven't read Mayor Idogawa's recounting of how he saw the white substance falling from sky like the snow after an explosion (that was Reactor 1 at Fukushima I Nuke Plant) as he tried to evacuate elderly citizens, go to my post from February 11, 2012.
From Jiji Tsushin (1/23/2013):
Futaba-machi, whose official functions have been moved to Kazo City in Saitama Prefecture after the Fukushima I Nuclear Power Plant accident, announced on January 23 that Mayor Katsutaka Idogawa offered to resign. The mayor's resignation will be official as of February 12, and the mayoral election will be held within 50 days after that date. The town assembly unanimously passed the no-confidence resolution against Mayor Idogawa in December last year, and the mayor in turn dissolved the assembly on December 26. The town faces an extraordinary situation where there is no head of the town nor the town assembly.
According to Futaba-machi, Mayor Idogawa gathered senior officials of the town to a meeting on January 23 where he expressed his intention to resign, and submitted the notice to the secretariat of the town assembly. Until the new mayor is installed, Vice Mayor Kazuyoshi Inoue will assume the duties of the mayor.
All residents of Futaba-machi, where Fukushima I Nuclear Power Plant is located, have evacuated the town after the nuclear accident. In March last year, the national government requested that Futaba, Okuma, and Naraha to accept intermediate storage facilities to be built in their towns, which would be used to store contaminated soil removed in the process of decontamination. The town assembly became suspicious of the mayor's intentions over the construction of such facilities [two in Futaba-machi] and submitted the resolution of no confidence [against the mayor].
Town assemblymen/women wanted to go ahead with the government plan, which would mean more money for the town. Mayor Idogawa said no, as he wanted the town's people to fully understand the implication of such facilities and decide for themselves.
Jiji article doesn't say why Mayor Idogawa is resigning. Mayor Idogawa has penned his farewell letter which is posted on the Futaba-machi website, but he does not say why he is resigning.
Mayor Idogawa has had hardly any support from anyone in his quest to secure a safe, radiation-free permanent place for the town residents, official or private, except for a few volunteers who occasionally cooked meals for the evacuees who still live in an abandoned high school building in Kazo City, Saitama.
It's been nearly two years after the start of the nuclear accident.