The Liberal Party is a political party in killer7. It is the opposition to the current United Nations Party government of Japan. Unlike the real-world Japanese Liberal Party, which is actually ideologically conservative in spite of its name, the Liberal Party is in fact liberal. Although it was once the dominant party in Japanese politics, the Liberal Party has lost most of its influence in recent years.
After a fusillade of nuclear warheads are launched on Japan, kicking off the events of Sunset, UN Party leaders dispatches two Liberal Party canvassers, Oota and Kuramoto, to meet with United States liaisons in an effort to convince the United States of Japan's continued usefulness and thus persuade her to deploy the Fireworks missile defence system. This meeting takes place at the KAKU building, a disused HQ of the UN Party. However, the talks break down when one of the participants cheats at the Mahjong game they are playing, resulting in a sudden Mexican standoff and the subsequent death of all four negotiators.
It is unknown what happened to the Liberal Party after the UN Party seized control of the Japan; given its totalitarian stance, it may have outlawed the organization and membership therein. However, the fact that Matsuoka dispatched Liberal Party agents to rendezvous with United States governmental representatives may suggest that the UN Party has under-the-table dealings with its political enemies, so it may have been unaffected.