Kim Nam Joon, the South Korean rapper, record producer and songwriter popularly known by his stage name Rap Monster, is celebrating his 23rd birthday on Tuesday, September 12.

Born in Ilsan New Town of Gyeonggi-do province, the BTS member began his musical journey with as an underground rapper and he was known by his stage name, Runch Randa. He joined the boy band in 2010.

The seven-member group, also known as Bangtan Boys or Beyond The Scene, shared several never-before-scene photos of their team leader on various social networking sites, including Twitter and Facebook, with the caption 2017 Rapmony Day.

Also read: Happy birthday Kim Nam Joon; check out 23 rare, unknown facts about BTS leader Rap Monster

BTS Army, the fan group of BTS, also sent messages and wishes to their favourite K-Pop idol under the hashtag Happy Namjoon Day. Check out some of the fan tweets below:

Meanwhile, a group of netizens claimed Jin is very popular among Korean gay community. A post titled "This idol member is quickly gaining crazy amounts of popularity among gay men in Korea. That popular idol? Was none other than BTS's Jin" has been doing the rounds online, reported Koreaboo.

While a section of his fans was surprised to see the post, a few others stated the K-Pop idol's beauty is unbeatable. The messages ranged from, "I never expected it to be Jin lol" to "His eyes...they pretty."

The seven member South Korean boyband group BTS at Billboard Music Awards 2017.Reuters

Apart from Jin, a 14-year-old Busan girl also captured the attention of many netizens for her messages about the Bangtan Boys. She was criticised by social media users for posting sexual comments directed at the young Korean heartthrobs.

BTS will release their mini-album Love Yourself Her on September 18. One of the tracks from the album, titled Best of Me, is being made in collaboration with The Chainsmokers.