 Mataichi was inaugurated into his 2-year term at the conclusion of the party conference on 25 February 2018.Contrary to initial prediction, incumbent Tadatomo Yoshida declined to run for another term as SDP leader, citing the need for the next leader to be an elected SDP lawmaker.As no one filed their candidacy before the original 12 January deadline, the submission deadline was extended to 26 January.