In 2008, Jinho won first place in the SM Everysing Contest. He later became a trainee through SM Entertainment's casting system in the same year. In November 2010, Jinho made his debut as a member of SM the Ballad alongside Super Junior's Kyuhyun, Shinee's Jonghyun, and TraxX's Jay. Despite the great reception, with the group's debut EP reaching number one on the charts, Jinho did not participate in any further activities with the agency after promotions for the group concluded that year.
2015–present: Departing SM Entertainment, debut with Pentagon and musical roles
In 2015, Jinho left SM Entertainment and began working as a singing tutor at Modern K Academy. Modern K Academy encouraged Jinho to audition at Cube, their CEO has close connections with Cube Entertainment and had a hand in creating Pentagon, being in charge of talent development. In February, he was part of a vocal project group, Seorin-dong Children with Hui and another female singer. They released a remake of and Ryu Keum-deok's 1994 classic "For All the New Lovers". The group wasn't originally supposed to consist of them, but after receiving a good response from Cube Artist Development for the recorded guide, the company decided to release it on streaming sites. Making it through the audition process, Jinho participated in making it to the final lineup and debuting with the group on October 10, 2016. In 2017, Jinho started a personal project titled "Magazine Ho" releasing covers in various genres and languages on the last of each month. With this project he has worked with and featured other artists such as CLC's Sorn, I-dle's Jeon So-yeon, and band mates Hongseok, Shinwon, Hui, and Kino. On March 17, 2018, Jinho held his first mini live concert which is a part of his 'Magazine Ho' cover songs project. In September, it was announced that Jinho would star in the musical Iron Mask as Raul, the son of Athos who admires his father and dreams of becoming a royal general. The musical ran from September 13 to November 18 at the Kwanglim Art Center, Seoul. He rotated the role with musical actor, Shin Hyun-mook and actor Yoo Hyun-seok. On December 17, 2018, Cube announced his second mini live concert "Magazine Ho Vol.2 - Ready Ho" would be on the 19th of January 2019 at Ilchi Art Hall, and it sold out in seconds. Members Hongseok and Kino were present as special guests during the concert. Jinho was cast in his fourth musical, Goddess is Watching You. He played as the role of an innocent and pure North Korean soldier Ryu Soon Ho, who overcomes his trauma due to war with the belief in a goddess. The musical ran from November 14, 2019 to February 26, 2020 at the Daehangno Arts Theater in Seoul. Jinho held his 3rd solo mini live concert, "Magazine Ho Vol.3 - Off Stage" on January 11, 2020. Due to high demand from fans, Cube entertainment added an additional date to the concert. Jinho is set to open the first performance on January 10 to meet more fans. He sang an unreleased song, "Gravity" together with member Kino which was composed and written by Kino. Members Hui, Hongseok and Yeo One were also present as special guest. In March, Jinho appeared on Mnet's music talk showStudio Music Hall 2. He was introduced as "high note terminator" performing a duet of Kim Kwang-seok's "At About Thirty". As part of his mandatory military service, Jinho enlisted as an active duty soldier on May 11, 2020.
