Xeno-T

Mixtapes were released in March and April 2012 to promote the group before debut.[3] The members were officially introduced in October 2013 and the group held a debut showcase on October 22, 2013.[4][5]

On October 22, 2013, they released their debut music video for lead single "Follow Me (말로해)", and a day later released their debut EP, Dogg's Out.[6][7] Topp Dogg released a repackaged version of Dogg's Out on December 12, which included the title track "Cigarette" and a Chinese version of "Follow Me".[8]

On January 13, 2014, Stardom Entertainment released a teaser for Topp Dogg's second EP.[9] On January 15, Topp Dogg made their comeback with the release of the music video to title track "Open the Door" and a second song entitled Arario was released the next day.[10] The music video for "Arario" was released on February 12, serving as the title track of their repackaged EP, which was released February 24.[11]

On June 9, it was revealed that Topp Dogg would be releasing their third EP, AmadeuS, with the title track "TOPDOG". However, a few days before the release, the entire album was leaked on the internet. The label attempted to remove the songs, and later took legal action against the culprit.[12][13]

On August 25, Topp Dogg released a repackage of AmadeuS with three new tracks and a short film showing fans the behind the scenes footage of the AmadeuS photoshoot.

For their first anniversary, Topp Dogg released a new "old school" song, "Annie" (short for "Anniversary"), on October 16.[14]

Topp Dogg's First Showcase 2015 Live in U.S., Houston

After months of Seogoong seemingly being on hiatus, he posted a message on Twitter and on Topp Dogg's official fancafe, revealing that he would be moving from Topp Dogg to its sub-unit "Under Dogg" so that he could "cover a broader musical spectrum". He began working under the sub-unit on January 16.[15]

Concerts for their American tour were held in Houston, Texas; Miami Beach, Florida; and Atlanta, Georgia during February 2015.[16]

As of July 2015, Topp Dogg was moved to Hunus Entertainment after their former company Stardom Entertainment had been acquired and merger by Hunus Entertainment.

On October 8, Hunus Entertainment released a statement after numerous rumors were surfacing over Kidoh and Gohn filing lawsuits against the company for "mismanagement of their careers" as the two members wanted to expand their careers. The statement confirmed the rumors that Gohn and Kidoh had both tried to file lawsuits against the company [17]

Before the release of their fourth EP, Hunus Entertainment released four teaser videos over the course of two weeks leading up to the release date of "Emotion", "O.A.S.I.S", "All Eyez on Me", and "The Beat". On October 19, Topp Dogg released their fourth EP, The Beat, along with a music video for the title track of the same name.[18] The EP peaked at number 22 on the Gaon Album Chart, selling 3,000+ copies.

On March 3, Topp Dogg released an OST for the TV series Come Back Mister; the track was also given a music video featuring the members recording the song. Two more songs were released for the drama by Topp Dogg members—the first being "Back Then" by Hojoon, released on March 31, and the second being "You" by Hojoon and Sangdo, released on April 7.

Topp Dogg's rap line (Yano, A-Tom and Jenissi) took part in season five of the popular rap survival show, Show Me the Money, which began airing in May.[19] A-Tom passed the audition process and made it to round two where he was eliminated. Shortly after A-Tom released a song to his SoundCloud entitled "So Blind", which was later uploaded to Hunus Entertainment's YouTube account on May 20. Both Yano and Jenissi failed to pass the audition round.

It was announced in May that Topp Dogg would be taking part in a web series created by K-Pop news website Soompi called Topp Dogg: All-Kill.[20] The show ran for 10 episodes, from May 23 to August 15, and aired on Mondays—it featured the members taking part in various "challenges" every week, such as cooking and charades, and featured special segments such as a dorm tour.[21][22][23]

On October 31, they released a comeback teaser for their first studio album First Street, as nine members instead of the previous ten. Jenissi was revealed to have left the group to pursue a solo career. The teaser of "Rainy Day" was released on October 31. The album along with the music video for the title track were released on November 7, 2016.

On February 28, 2017 Hunus Entertainment announced that A-Tom had temporary left the group to participate in Produce 101 Season 2 under his birth name, Kim Sang-gyun. He was eliminated in 26th place during the third elimination round.[24]

On September 29, Hunus Entertainment released a statement on the group's fan cafe, announcing that five members (Sangdo, Xero, B-Joo, Yano, and Hojoon) would be participating in the reality television series The Unit. A-Tom was announced to be debuting with the Produce 101 fan-created group, JBJ and his future activities with Topp Dogg had remained to be discussed after his activities with JBJ came to an end. Following promotions for their first studio album, First Street, Hansol, P-Goon and Nakta were revealed to have left the group. Hansol intended to join the military. His contract with Hunus is to be discussed once he is discharged. P-Goon also planned to enlist in the military, with plans to pursue an acting career upon being discharged. Nakta had decided to terminate his contract to pursue a solo career.[25]

In October 2017, the remaining five members joined the audition process for The Unit, with only Hojoon and B-Joo passing.[26] Hojoon was eliminated in 39th place during the second elimination round[27] while, B-Joo was eliminated in 25th place during the third elimination round.[28]

On February 21, it was announced via Topp Dogg's official fan cafe that the group were starting fresh, as a new group under the name of Xeno-T. The name is a combination of "xenogeneic" and "top-class", the latter being a tribute to their fandom, "ToppKlass". The post revealed that the group wanted a new start to showcase themselves better as a group and show new sides to themselves. It was also announced that B-Joo would be changing the Korean writing of his stage name, and that Yano would now be promoting under his birth name, Sangwon.[1] Hunus later confirmed that A-Tom would not be joining the group once his activities with JBJ came to an end.[29]

XENO-T officially debuted in Japan with their first Japanese single, "どこにいても" (Wherever You Are) on May 30, along with the release of the music video.[30]

• Hojoon (호준)
• Sangdo (상도)
• B-Joo (비쥬)
• Xero (제로)
• Sangwon (상원) (formerly known as Yano)

• Seogoong (서궁)
• Kidoh (키도)
• Gohn (곤)
• Jenissi (제니씨)
• P-Goon (P군)
• Nakta (낙타)
• Hansol (한솔)
• A-Tom (아톰)