A six-day extraordinary Diet session kicked off Friday with the Upper House electing a president from the Liberal Democratic Party for the first time since 2007.

It is also the first time since 2007 that the LDP-led ruling coalition has control of both chambers thanks to its landslide victory in last month's Upper House election.

The LDP suffered a crushing defeat in the 2007 Upper House election during Shinzo Abe's first stint as prime minister and it had been a minority force ever since.

The coalition government of the LDP and New Komeito has high hopes that regaining control of both chambers will prevent the opposition camp from delaying or boycotting Diet procedures.

But this extra session is likely to focus on housekeeping matters, such as electing the Upper House president and vice president, as well as appointing committee chairs. Serious legislative work will likely wait until the extraordinary session slated for October.

At their plenary session Friday, the Upper House lawmakers elected Masaaki Yamazaki of the LDP as their president and Azuma Koshiishi of the Democratic Party of Japan as their vice president.

Although the coalition camp's comfortable majority in the upper chamber entitles it to all 17 committee chair positions, it agreed to allocate some of the chairmanships to opposition parties.

However, the DPJ failed to fill its allotted position Friday because it has yet to pick a lawmaker to replace Koshiishi as head of the party's caucus in the Upper House.

"We have never had a situation like this where all of the committee chairs could not be appointed" on the first day, LDP Secretary-General Shigeru Ishiba complained at a news conference.