Seo In-guk

In 2009, Seo competed in the Mnet singing contest Superstar K, winning the show's first season.[5] The subsequent spotlight came with a hectic schedule of recording, photoshoots, interviews and television appearances as well as chart-topping singles and albums.[6] Seo also faced negative consequences of media attention, including rumors of plastic surgery and "cold shoulder" treatment from the three major Korean networks, as he was a cable television star.[7][8]

In 2012, Seo was part of the cast of the jukebox musical Gwanghwamun Love Song[9] and made his onscreen acting debut with a supporting role in KBS's Love Rain.[10][11] He also signed with Japanese agency Irving Entertainment.[12] He landed his first leading role later that year, in cable channel tvN's '90s nostalgic hit drama Reply 1997. Seo's portrayal of a teenage boy in unrequited love with his childhood best friend won praise from both audiences and critics.[13][14][15] He also recorded two singles for the soundtrack (both duets with co-star Jung Eun-ji), and one of them, "All For You", which is a remake of the song by "Cool" became one of the best-selling singles of the year on the Gaon Single Chart.[16][17] Shortly after, he appeared in MBC's weekend drama The Sons (also known as Rascal Sons).[18][19][20]

In November 2013

Seo joined the newly launched reality/variety show I Live Alone from January to June 2013.[21] He returned to the music scene in April 2013 with the single With Laughter or with Tears, the first soulful ballad from his discography.[22] Several weeks later, the song was followed by his Japanese debut with the release of the single Fly Away.[23][24]

In June 2013, he was cast in Master's Sun, a drama series written by the Hong sisters, playing a former soldier who served in the Zaytun Division who becomes the head of security for a shopping mall company.[25][26] In October 2013, he starred in his first big-screen leading role in No Breathing, a coming-of-age film about two swimming rivals, alongside Lee Jong-suk and Kwon Yuri.[27][28] He then played a dual role in Another Parting, a five-episode miniseries about a man and a woman who meet in the final moment of their lives and spend one special day together. Produced by LOEN Entertainment, the drama premiered on February 17, 2014 on Taekwang Group-owned cable channel Dramacube (also airing on BTV and YouTube).[29]

In December 2012

In 2014, Seo released his first Japanese album titled Everlasting, which comprises his previously released singles “Fly Away” and “We Can Dance Tonight”.[30] The album also features a new track titled “Everlasting Love” with a total of 12 tracks. The album debuted at number nine on the Oricon Daily Chart.[31] Seo later won the Best 3 New Artists (Asia) award at the Japan Gold Disc Awards.[32]

The same year, Seo headlined another cable romantic comedy series High School King of Savvy, in which he played a high school student and star hockey player who leads a double life when he's forced to take on his older brother's job as an executive at an IT company.[33][34][35] Later that year, Seo starred in his first period drama The King's Face, playing illegitimate crown prince Gwanghae, who becomes his father King Seonjo's rival in politics and love.[36]

In 2015, Seo joined the cast of SBS variety show Law of the Jungle from March to May, for the Indochina season.[37] He was then cast as a genius profiler in the police procedural/romance series Hello Monster which premiered in June 2015 on KBS2.[38] Later that year, he participated alongside other artists on Jellyfish Entertainment's collaborative track “Love In The Air” (Korean: 사랑난로) for the album Jelly Christmas 2015 – 4랑.[39]

In 2016 Seo joined Law of the Jungle for the second time for the show's Mongolia season.[40] He also starred in OCN's workplace drama Squad 38, playing a professional swindler.[41][42] The drama became the highest rated drama for OCN, and Seo won a special award or his role at the 11th Asian TV Drama Conference.[43] He then took on the leading role in MBC's romantic comedy Shopaholic Louis.[44]

On August 4, 2017, it was confirmed that Seo's contract with Jellyfish Entertainment had expired and that he would not be renewing his contract.[45] On August 7, it was announced Seo had signed with BS Company.[46]

In 2018, Seo was cast in The Smile Has Left Your Eyes, an adaptation of the 2002 Japanese television series Sora Kara Furu Ichioku no Hoshi.[47][48]

In 2019, Seo was cast in the crime thriller film Pipeline by Yoo Ha.[49]

In February 2017, it was announced that Seo received his official military enlistment date, set to take place on March 28. He'd previously pushed back his enlistment twice, starting in March 2015 and he gave his condition as a reason. Neither the media nor his management company states he did or didn't receive treatment though. But he'd passed a physical to enlist. It was reported he would enter his two-year military service quietly, without media coverage. Seo opted, instead, to release a music video for his self-composed song, "Better Together", written to his fans. The video was released on YouTube on March 26, 2017.[50] However, due to a fractured ankle, Seo was excused from mandatory military service just four days after entering the military and was scheduled for a medical re-examination to determine if he was fit to return to the military. His agency released the results of his medical re-examination, revealing Seo was diagnosed with Osteochondritis dissecans, a bone and cartilage condition. He was subsequently declared at a Grade 5 health rating and became exempt from military duty as a result.[51][52]