RM's birthday: Here is why BTS' Kim Namjoon changed his name

In 2017, Kim Namjoon stated that he would no longer use Rap Monster's stage name and would instead adopt the name RM. 

On September 12, BTS frontman RM, whose real name is Kim Namjoon, turned 27. The South Korean rapper was the first member of the seven-member group to be recruited, and he has led them ever since. Rap Monster was his stage name when he first debuted.

However, in 2017, Kim Namjoon stated that he would no longer use Rap Monster's stage name and would instead adopt the moniker RM.  In a statement posted on BTS's official fan café, he stated that RM looks more in tune with the music he wants to create and provides a wider range.

According to Soompi, he has been marketing under the alias Rap Monster for nearly five years, from the end of 2012. It was a stage name that he organically became known by among the company's family members and members, based on a lyric in a song he'd written as a trainee and became fond of. He went on to say that after he started marketing, the moniker 'BTS's Rap Monster' became too lengthy, and he began addressing himself as Rapmon or RM rather than the full name Rap Monster.

Later, for promotional purposes, he changed his name to 'RM,' which he believed was better in line with the music he'd be striving for and covered a broader range. He assumed that because he had previously released some songs and mixtapes as RM, some of his fans would have guessed this.

In his letter's conclusion, RM expressed his discomfort at altering his stage name, which he had used since before my debut. He thanked his followers and asked them to greet him under his new identity.

With RM's birthday, BTS fans have flooded him with well wishes and affection on social media. He turned to Twitter and posted three photos of himself, along with a letter of thanks.