Shinjiro Koizumi, chairperson of the ruling Liberal Democratic Party's election strategy committee, resigned on Monday following the LDP and Komeito coalition's failure to secure a majority in Japan's lower house election.

He said at the party headquarters that it is only natural for the election strategy committee chairperson, who led the campaign with set goals, to take responsibility when those goals are not met.

Opposition parties and others had secured 250 seats, surpassing the majority threshold of 233, while the ruling coalition held a total of 215 seats — 191 for the LDP and 24 for Komeito.

The LDP's seat count sharply declined from 247 before the election to 191, while the main opposition, the Constitutional Democratic Party of Japan, surged from 98 seats to 148.

Japanese Prime Minister and LDP President Shigeru Ishiba had set the coalition's majority in the House of Representatives as the victory threshold for the election on Sunday.

Ishiba himself faces challenges but plans to request cooperation from parties with which he can agree on policies to continue his administration.

It was his decision to dissolve the House of Representatives, which had been scheduled to last till next year, immediately after assuming the office of prime minister. His decision also marked the shortest time span between a new prime minister taking office and the end of the current lower house's term in Japan's history.