Liberals took over parliament in South Korea

The liberal Minjoo Party has won elections in South Korea against the ruling Saenuri Party, who for first time in 16 years lost control over parliament. Six parties were involved in the fight for 300 seats - the conservative Saenuri, The Minjoo Party of Korea (the main opposition liberal party), the People's Party (formed in early 2016 as a result of a split in The Minjoo Party), as well as the left-progressive Party of Justice. In addition, the Christian-Liberal Party and center-left party have put forward a candidate. In order to gain a majority, having a sweeping win in one of the provinces is sufficient. Up until now, most places have been occupied by the Saenuri Party, which had 152 seats.
The democratic facade
These elections were held against a background of a deep political crisis. In 2013, the Constitutional Court banned the Unified Progressive Party due to their alleged links with North Korea. This led to a reorganization of the opposition.
During the campaign period, the Saenuri Party pursued a policy of confrontation with North Korea, while the Minjoo Party took a more moderate position, especially arguing the need to work with the Kaesong industrial complex. The Minjoo Party also wants to resume inter-Korean business and people-to-people exchange
However, the Saenuri Party opposes the legalization of homosexuality, calling it "an outrage against humanity", while The Minjoo Party actively supports the practice.
Possible changes
South Korea is a presidential republic. Current president  Park Geun-hye is a member of Saenuri, so change within parliament will not directly influence government's politics, exept the legislation.
So the main change in country’s politics is expected in the realm of values. Rapprochement with North Korea is hardly realizable, because of hostile position of the President as well as the United States.
Previously however,  the main opposition Minjoo Party of Korea and People’s Party have pledged to restore operations at Kaesong industrial complex as well as restart six-party talks, which also involve the US, China, Russia and Japan.
It is expected that relations with Japan will become little more strained, because of the Minjoo Party’s pledge to renege and renegotiate a December settlement with Tokyo on the wartime sex slavery issue. However it will not change its strategic orientation towards the US, which wants a more active Japan in the region to counterbalance China’s influence.
Experts have taken notice of the fact that national security concerns seemed to have played a less prominent role in this South Korean election than they did in the past. The opposition benefited from the failed economic policies of the previous government.
Without a real alternative
Being in fact a US colony with limited rights and only a pseudo-sovereignty, South Korea is not able to independently determine its geopolitical areas of development, as the entire political debate is limited to the discourse permitted by Washington. Although the majority of South Korea’s citizens understand the need to normalize relations with its northern neighbor, and reunite the now divided nation, the country has criminalized expressing any sympathy for Pyongyang.
The regional situation
The elections were held against a background of deteriorating relations between the two Koreas and the growing tensions not only on the peninsula, but also in East Asia. The US is increasing its military presence, ostensibly justifying it by the allegations of aggressive behavior on the part of North Korea, while China suspects that much of this show of force is directed towards Beijing.