JYJ (previously known as JUNSU/JEJUNG/YUCHUN) is a trio, formed by former members of the South Korean boyband 동방신기 / 東方神起 (TVXQ) : Jaejoong (영웅재중/김재중), Yoochun (믹키유천), and Junsu (시아준수).

The three members of TVXQ filed a lawsuit in mid-2009 against their South Korean record label, SM Entertainment, arguing that the 13-year length and structure of their exclusive contracts as well as the terms of profit distribution were unilaterally disadvantageous towards the artists and should be invalidated.

The Seoul Central District Court in October, 2009 ruled in their favor on this matter.Following the hiatus of TVXQ, the three member group was announced under the name of 'JUNSU/JEJUNG/YUCHUN' in April 2010 by Rhythm Zone.

The trio kicked off their activities with a Japan Tour ‘THANKSGIVING LIVE IN DOME’ in May and June and appearances at the annual A-nation lives in Japan during the summer. The trio also released a personal travel documentary of all three members titled ‘3HREE VOICES’ and a mini- album, 'The…'.

In September 2010, Avex Entertainment announced the suspension all of JYJ's Japanese activities. Avex claims this stems from issues the label had with the president of the group's Korean management, C-JeS Entertainment.

JYJ stated it was a conflict over new terms demanded by Avex in contract renegotiation.The group released their English-language global debut album, The Beginning, under the name 'JYJ' in October 2010.

A worldwide album showcase tour was announced, touring Southeast Asia cities as well as the United States. A 2-day special concert ‘JYJ Worldwide Concert in Seoul’ was held at the Jamsil Olympic Stadium from November 27-28 after the World Showcase.

They were further met with positive feedback following the release of The Beginning. JYJ was featured on the cover of Billboard magazine and ranked by its readers as the 5th top album of 2010.JYJ followed up in January 2011 with another EP in the format of a "Music Essay" entitled "Their Rooms "Our Story".

In the spring of 2011, JYJ launched their first Worldwide Tour as a group with concerts held in Thailand, Taiwan, China, Canada, and the United States. In addition, JYJ held 2 rounds of a special charity concert in Toyko to benefit those affected by the Tōhoku Earthquake and two special encore concert performances in South Korea.

After a break for the members' individual activities, JYJ released their second group album and first Korean language album entitled "In Heaven" in September 2011.JYJ extended their first Worldwide Tour in October & November of 2011 by adding European stops in Barcelona and Berlin and holding two rounds of a larger Japanese concert at Hitachinaka.