In April 2016 Hamada resigned from the Party for Japanese Kokoro and joined Initiatives from Osaka. Hamada's Tottori constituency was to be merged with the Shimane at-large district to create the Tottori-Shimane at-large district and contesting the new seat as a minor party candidate against Kazuhiko Aoki, the LDP's incumbent member for Shimane, would prove too difficult. Instead Hamada received a nomination to contest the summer 2016 election from the national proportional representation block as an Initiatives from Osaka candidate. However, on Friday 27 May 2016 Hamada caused controversy when he was absent from the House of Councillors, which was debating bills related to relief following the 2016 Kumamoto earthquakes, in order to attend a party meeting in Osaka for Osaka prefectural representatives. He greeted the meeting by saying "I have come today to say a greeting to the all-star cast in attendance". His attendance was intended to gain support within the party for his national block campaign, and Hamada later explained that he had the party's permission to be absent from the House debate. However, the party's leader in the Osaka Prefectural Assembly, Kazunori Ohashi, said the party was unaware of his intended absence. On the following Monday, party secretary-general announced that the party had removed Hamada as a candidate, saying that his absence from the House in order to progress his re-election campaign was "extremely regrettable". Hamada submitted his resignation to the party on the same day, which was accepted the following day, 1 June 2016.