The opposition Democratic Party of Japan held a self-deprecating convention Saturday, inviting more than 500 people aged under 30 to criticize their three-year rule in an effort to garner more support from young voters ahead of the Upper House election.

The unusual meeting was initiated by young DPJ lawmakers who felt a strong urge to reflect on their mistakes as a way to help restore the party, which was ousted from power in a landslide defeat in December's Lower House election.

The event was streamed live on the Nico Nico Douga video-sharing website and drew more than 10,000 viewers as ranking party members including former Prime Minister Naoto Kan, former Chief Cabinet Secretary Yukio Edano and former Health, Labor and Welfare Minister Akira Nagatsuma took questions coming in via cellphones.